https://navigators.di.fc.ul.pt/w2/index.php?title=Special:Contributions&feed=atom&limit=20&target=TribeiroNavigators - User contributions [en]2024-03-29T11:24:27ZFrom NavigatorsMediaWiki 1.16.5https://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-08T14:23:58Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">27/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Miguel Garcia</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will make a dry-run of my PhD defense, therefore I am hoping to receive (most of) the harsh comments before the D-day!<br />
My PhD thesis addresses a long-standing open problem of managing Byzantine Fault Tolerance (BFT) systems. This is a fundamental problem because BFT protocols assume that replicas fail independently. In this thesis we investigated how this assumption can be substantiated in practice by exploring diversity when managing the configurations of replicas.<br />
">Diverse Intrusion-tolerant Systems</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Miguel Moreira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="...">...</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px" style="color:Tomato;"><strong>22/05</strong></td><br />
<td style="width:300px" style="color:Tomato;"><strong>Pedro Ferreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="color:Tomato;"><strong>22/05</strong></td> <br />
<td style="color:Tomato;"><strong>Vinicius Cogo</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Tiago Correia</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-08T14:18:06Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">27/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px" style="color:Tomato;"><strong>08/05</strong></td><br />
<td style="width:300px" style="color:Tomato;"><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="color:Tomato;"><strong>08/05</strong></td> <br />
<td style="color:Tomato;"><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Tiago Correia</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:59:19Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">27/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px" style="color:Tomato;"><strong>08/05</strong></td><br />
<td style="width:300px" style="color:Tomato;"><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="color:Tomato;"><strong>08/05</strong></td> <br />
<td style="color:Tomato;"><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:57:27Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">27/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px" style="color:Tomato;">><strong>08/05</strong></td><br />
<td style="width:300px"style="color:Tomato;">><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td><strong>08/05</strong></td> <td><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:53:44Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">27/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px"><strong>08/05</strong></td><br />
<td style="width:300px"><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td><strong>08/05</strong></td> <td><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:50:10Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">27/03</td><br />
<td style="width:300px">Nuno Dion&iacute;sio</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="To be prepared against cyber-attacks, most organizations resort to security information and event management systems to monitor their infrastructures. These systems depend on the timeliness and relevance of the latest updates, patches and threats provided by cyberthreat intelligence feeds.<br />
Open source intelligence platforms, namely social media networks such as Twitter, are capable of aggregating a vast amount of cybersecurity-related sources. To process such information streams, we require scalable and efficient tools capable of identifying and summarizing relevant information for specified assets.<br />
In this talk, I will present a processing pipeline based on deep learning algorithms to identify and extract relevant information from tweets. The contents of this talk are based on a paper recently accepted for the conference IJCNN (International Joint Conference on Neural Networks).<br />
">Cyberthreat Detection from Twitter using Deep Neural Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk I will argue in favour of introducing contests (think “The Voice”, for instance) into the programming assignments (PAs) of our courses. I will discuss how they can help both teaching and research, by promoting reproducibility and (potentially) even provide lasting advances! I will introduce the congestion control contest: the second PA of our “advanced computer networks” (PRD) MSc course. And it will include a demo, as usual!<br />
">My network protocol is better than yours!</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- Andr&eacute; Oliveira????????? ###############################################################<br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px"><strong>08/05</strong></td><br />
<td style="width:300px"><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td><strong>08/05</strong></td> <td><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:38:46Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px"><strong>08/05</strong></td><br />
<td style="width:300px"><strong>Miguel Moreira</strong></td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td><strong>08/05</strong></td> <td><strong>Miguel Garcia</strong></td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:36:06Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px"><H2>08/05</H2></td><br />
<td style="width:300px">Miguel Moreira</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Miguel Garcia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:35:22Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px"><B>08/05</B></td><br />
<td style="width:300px">Miguel Moreira</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Miguel Garcia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-05-07T22:30:42Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Miguel Moreira</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Miguel Garcia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-04-10T13:08:18Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-04-10T13:07:26Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="SIEMs are powerful systems that can improve a company's security by reducing incident response time, neutralizing threats, and centralizing much information about its infrastructure and devices.<br />
However, since most SIEM systems are deployed locally for security purposes, their events are stored for short periods due to limited local storage capacity, discarding them after 12 months, sometimes less.<br />
Cloud storage could be a cheap option for storing these old events as they can help solve many persistent incidents such as zero-day threats, which can take years to discover. The main problem in using cloud storage for sensitive data is that providers are exposed to security leaks and attacks, which pushes away this category of users.<br />
In this talk, I will introduce the SLiCER system, a low cost solution that combines event processing, storage and retrieval in a safe and inexpensive way. It can work as a background system to extend the storage capacity of SIEMs for long periods.<br />
">SIEMs</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this NavTalk I will speak a little bit about classical consensus and Proof-of-Work consensus, what is it, its premises and how they work,<br />
some challenges regarding the approaches and a brief comparison about them.<br />
I will bring some works which try to scale the classical BFT consensus and improve PoW performance. ">BFT Consensus & PoW Consensus (blockchain). </span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-03-13T14:59:23Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Fernando Ramos</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="We all have to give research talks once in a while -- like when we do a Navtalk -- so I think it’s good to share experiences and identify techniques that work, and give advice on those that usually do not. I was personally very much influenced by a superb talk by Simon Peyton Jones on this topic, so in this talk my goal is to share his own talk. I hope this talk to be highly interactive, so I hoping many will also share your own experiences and opinions.">How to give a great -- OK, at least a good -- research talk</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-03-13T14:54:22Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-03-13T14:53:40Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Web applications are an important part of our everyday lives and, like any other software, they are prone to vulnerabilities. Given that they are accessible for many users, it is of the utmost importance to ensure that vulnerabilities are removed from them. Unfortunately, many developers are unaware of the correct way of fixing certain vulnerabilities. For this reason, a tool capable of automatically correcting these applications would be greatly beneficial for their security. In this talk, I will show some of the reasons why vulnerabilities are introduced, and why developers are misinformed about them. I will also present the current status and main challenges of the work I am currently performing.">Automatically correcting PHP web applications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-02-19T14:35:35Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">08/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>08/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>22/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">05/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>05/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">03/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>03/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>17/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-02-19T14:27:28Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">15/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">12/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>12/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">10/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-02-19T14:07:22Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">13/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>13/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>27/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">10/04</td><br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td>01/05</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>01/05</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td style="width:100px">15/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">12/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>12/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">10/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>10/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>24/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-02-19T11:22:34Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk, I will introduce a type of graphical models called Conditional Random Fields, and motivate why it has a good application in finding software vulnerabilities. I will specifically explore vulnerabilities in web applications due to their increasing relevance and damage dimension. This work intends to facilitate the developers’ task of identifying vulnerabilities in the code.">Conditional Random Fields and Vulnerability Detection in Web Applications</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <br />
<td>Jo&atilde;o Sousa</td><br />
<td><span style="border-bottom: dashed 1px #000" title="The recent popularization of permissioned blockchains systems lead to a resurgence of interest in the Byzantine fault-tolerant (BFT) state machine replication technique. Such interest is the prime motivation behind kickstarting development on version 2.0 of BFT-SMaRt, a BFT state machine replication library created by the Navigators group. Specifically, BFT-SMaRt v2 will provide a new state management layer dubbed SMaRtChain, which creates and maintains a ledger, effectively rendering the library a blockchain platform. This talk aims at presenting the current status of BFT-SMaRt v2, focusing in the aforementioned SMaRtChain layer, as well as in a recently implemented mechanism to enforce flow control in respect to excessive workloads, a scenario that can affect quality of service as observed by clients.">Towards BFT-SMaRt v2: Blockchains and Flow Control</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">12/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>12/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">09/04</td> <br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">14/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>14/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">11/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">09/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-01-29T11:21:55Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">Title Here</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk I will motivate the need for a change of paradigm in networking: towards self-driving networks. But, most importantly, I will try to convince you that the prospect for this new generation of networks is, at the moment of writing, excruciatingly poor. The talk will include demos and quizzes, to try to move your thoughts away from the yummy pizza that follows.">Networks that drive themselves…of the cliff</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td><span style="border-bottom: dashed 1px #000" title="In 1983, two SOSP Program Committee members published: An Evaluation of the Ninth SOSP Submissions -or- How (and How Not) to Write a Good Systems Paper, ACM SIGOPS Operating Systems Review (available in SOSP and OSDI websites). In this talk, I will present most of their recommendations in a concise way. This article and talk should be useful for anyone that wants to submit a paper on a (systems) top-conference.">Some tips before rushing into LaTeX (adapted from: How (and How Not) to Write a Good Systems Paper)</span></td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <td>Jo&atilde;o Sousa</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">12/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>12/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">09/04</td> <br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">14/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>14/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">11/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">09/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeirohttps://navigators.di.fc.ul.pt/wiki/NavTalksNavTalks2019-01-24T13:10:10Z<p>Tribeiro: </p>
<hr />
<div><p>The NavTalks is a series of informal talks given by Navigators members or some special guests about every two-weeks at Ciências, ULisboa.</p><br />
<br />
<p><i>Leave mouse over title's presentation to read the abstract.</i></p><br />
<!--<span style="border-bottom: dashed 1px #000" title="">TESTE</span>--><br />
<br />
<!-- <br />
###########################################################<br />
############## PAST PRESENTATIONS #########################<br />
########################################################### --><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h2><strong>Past presentations</strong></h2><br />
<h3><strong>September 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Alysson Bessani</td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The blockchain has emerged as a disruptive paradigm to build decentralized transactional applications such as cryptocurrencies. The core of the technology is the consensus algorithm used to order blocks of transactions in a Byzantine fault-tolerant (BFT) way. There are two basic classes of such algorithms: Nakamoto consensus (employed in Bitcoin and other permissionless systems), which requires peers to solve a cryptographic puzzle to propose new blocks and eventually converge to a single chain; and “traditional” BFT consensus (used in permissioned systems), which employs well-known protocols for reaching agreement in a closed set of known processes. The former scales to 10000s of nodes but can process only a few transactions/s with a latency of hours, while the latter performs much better, but only with a few dozens of nodes. Recently, many hybrid consensus protocols have been proposed. They merge these two classes to achieve both scalability and performance. Although promising, they are still subject to limitations coming from their building blocks (e.g., high latency and power consumption). SMaRtChain aims to devise a set of radically different consensus protocols for both permissioned and permissionless blockchains. First, we plan to extend the Consensus with Unknown Participants paradigm to adapt it for open blockchains, aiming to overcome the limitations described above. Second, we want to design new scalable and high-performance BFT consensus algorithms based on solid theoretical building blocks for 1000s of nodes (enough for hybrid and permissioned blockchains) and capable of processing 1000s of transactions/s with sub-second latency. We will implement and integrate these contributions into existing open-source blockchain platforms (e.g., Fabric, Corda) for maximum impact. Finally, we will investigate and address the limitations of existing blockchains to support applications requiring big data, machine learning, and integration with the internet of things."><br />
SMaRtChain: A Principled Design for a New Generation of Blockchains</span></td> <br />
<td style="width:30px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">20</td><br />
<td style="width:300px">Rui Miguel</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="The Internet today is mainly used for distributing content, in a fundamental departure from its original goal of enabling communication between endpoints. As a response to this change, Named Data Networking (NDN) is a new architecture rooted on the concept of naming data, in contrast to the original paradigm based on naming hosts. This radical architectural shift results in packet processing in NDN to differ substantially from IP. As a consequence, current network equipment cannot be seamlessly extended to offer NDN data-plane functions. To address this challenge, available NDN router solutions are usually software-based, and even the highly-optimised designs tailored to specific hardware platforms present limited performance, hindering adoption. In addition, these tailor-made solutions are hardly reusable in research and production networks. The emergence of programmable switching chips and of languages to program them, like P4, brings hope for the state of affairs to change. In this presentation, we present the design of an NDN router written in P4. We improve over the state-of-the-art solution by extending the NDN functionality, and by addressing its scalability limitations. A preliminary evaluation of our open-source solution running on a software target demonstrates its feasibility."><br />
Named Data Networking with Programmable Switches</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>October 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Bruno Vavala (Research Scientist in Intel Labs) </td> <br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="I will present Private Data Objects (PDOs), a technology that enables mutually untrusted parties to run smart contracts over private data. PDOs result from the integration of a distributed ledger and Intel Software Guard Extensions (SGX). In particular, contracts run off-ledger in secure enclaves using Intel SGX, which preserves data confidentiality, execution integrity and enforces data access policies (as opposed to raw data access). A distributed ledger verifies and records transactions produced by PDOs, in order to provide a single authoritative instance of such objects. This allows contracting parties to retrieve and check data related to contract and enclave instances, as well as to serialize and commit contract state updates. The design and the development of PDOs is an ongoing research effort, and open source code is available and hosted by Hyperledger Labs (Linux Foundation).">Private Data Objects</span></td> <br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">4</td><br />
<td style="width:300px">Marcus Völp (Research Scientist, CritiX, SnT, Univ. of Luxembourg) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="As you are well aware, many practical concerns in systems aiming at Byzantine fault and intrusion tolerance require reaching consensus in difficult situations. For example, to remain exhaustion safe, replacing permanently damaged replicas requires relocating the replicated functionality to a fresh set of spares, necessitating conensus on the new group of active replicas. While group membership protocols exists for this task, we are also aware of their limitations (faults in the adaptation infrastructure (recurring the problem in the servers implementing it), operation modes that cannot reach consensus (aka Cheap / ReBFT minimal mode), etc.) that make it extremely difficult (if not impossible) to perform these reconfigurations in a reliable manner. In this talk, I would like to give you an overview over some of the current (unsolved) research problems we work on in CritiX and which I would like to discuss with you while here. I would like to share my view on our hinge that in some of the above settings, there is still hidden an impossibility result, possibly rendering CheapBFT (or at least generalizations of it to arbitrary quorums) incorrect, but motivating a novel design principle, which we call reflective consensus: Rather than solving the difficult, but naturally arising consensus problem (e.g., consensus on group membership in case of exhaustion failure due to an increasing threat level), we reflect consensus to the same set of replicas where it will occur, but in a simpler version that is possibly even executed at a different time (e.g., proactively when the system is not yet exhaustion failed)."><br />
Reflective Consensus</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center" style="width:100px">18</td><br />
<td style="width:300px">Yair Amir (Professor, Johns Hopkins University) </td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Emerging applications such as remote manipulation, collaborative virtual reality, or remote robotic surgery require communication that is both timely and reliable, but the Internet natively supports only communication that is either completely reliable with no timeliness guarantees (e.g. TCP) or timely with only best-effort reliability (e.g. UDP). We present an overlay transport service that can provide highly reliable communication while meeting stringent timeliness guarantees (e.g. 130ms round-trip latency across the US) over the Internet.<br />
<br />
To enable routing schemes that can support the necessary timeliness and reliability, we introduce dissemination graphs, providing a unified framework for specifying routing schemes ranging from a single path, to multiple disjoint paths, to arbitrary graphs. Based on an extensive analysis of real-world network data, we develop a timely dissemination-graph-based routing method that can add targeted redundancy in problematic areas of the network. We show that this approach can cover close to 99% of the performance gap between a traditional single-path approach and an optimal (but prohibitively expensive) scheme."><br />
Timely, Reliable, and Cost-Effective Internet Transport Service using Structured Overlay Networks</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>November 2018</strong></h3><br />
<table border="0.5" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td align="center" style="width:100px">13</td><br />
<td style="width:300px">Salvatore Signorello</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Today's Internet dominant usage trends motivate research on more content-oriented future network architectures. Among the future Internet proposals, the Information-Centric Networking (ICN) research paradigm aims to redesign the Internet's core protocols focusing on contents rather than on hosts. Among the ICN architectures, the Named-Data Networking (NDN) forwards and records users' content requests by their names in routers along the path from one consumer to 1-or-many content sources. The Pending Interest Table (PIT) is the NDN's router component which temporarily records forwarded requests. On one hand, the state in the PIT enables properties like requests aggregation, multicast responses delivery and native hop-by-hop control flow. On the other hand, the PIT stateful forwarding behavior can be easily abused by malicious users to mount disruptive distributed denial of service attacks (DDoS), named Interest Flooding Attacks (IFAs). In IFAs, loosely coordinated botnets flood the network with a large amount of hard-to-satisfy requests with the aim to overload both the network infrastructure and the content producers. In this talk I will summarize the state of the art on the design of countermeasures against the IFA, an NDN-specific security threat to which I devoted much of my PhD research. First, I will introduce existing defense mechanisms and main flaws in the mainstream approach to the defense against this attack. Secondly, I will present some other techniques I propose to counteract certain IFAs, whose design has not been completed yet. Finally, I will share a few more research directions that can be pursued to design more robust forwarding planes for a certain class of ICNs."><br />
The Past, the Present and some Future of Interest Flooding Attacks in Named-Data Networking</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">13</td><br />
<td>Tiago Oliveira</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Data is the new gold, and storing it brings new challenges. Nowadays, more and more companies are moving their data centres to the cloud, especially because it is cost-effective, easily scalable and remove a lot of management efforts. However, at the same time, current cloud storage solutions have some limitations: (1) they are not totally reliable - we have seen major reports of outages; (2) they not fit to every customer’s needs - businesses have a huge data diversity which probably require different levels of security, availability and costs; and (3) they are not fully private - most of the cloud storage solution have access to the users files. <br />
To respond to this, we have developed Vawlt, an innovative technology for secure and private data storage in the cloud that eliminates all the aforementioned limitations by combining a multi-cloud environment with a serverless design, while employing zero-knowledge encryption mechanism and being full customizable. In this talk I will present our MVP (Minimum Viable Product) that we have launched in the beginning of October."><br />
Vawlt - Privacy-Centered Cloud Storage</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
<tr><br />
<td align="center">27</td><br />
<td>Nuno Neves</td><br />
<td><span style="border-bottom: dashed 1px #000" title="Usaremos um cenário de uma Casa Inteligente para encontrarmos uma vulnerabilidade de software, e compreendermos o impacto que poderia ter nas nossas vidas. Seguidamente, iremos recorrer a algumas técnicas, que incluem a aprendizagem máquina, para descobrir e corrigir automaticamente o software destas vulnerabilidades. Terminaremos com desafios futuros na área de blockchain e software crítico multi-versão.">Segurança de Software - Como Encontrar uma Agulha num Palheiro?</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td align="center">27</td><br />
<td>Ricardo Mendes</td><br />
<td><span style="border-bottom: dashed 1px #000" title="When building Vawlt, our goal was to create the most secure and private cloud storage service available. To achieve this, we created a Zero-knowledge End-to-end Encryption protocol that ensures the data clients store is private and only accessible them. It makes it impossible for both clouds or Vawlt to have functional access to the data stored or shared among clients. All of this without compromising the multicloud and serverless nature of Vawlt. In this talk, I will present this protocol, our strategies, and the techniques used.">Vawlt - The Zero-knowledge End-to-end Encryption Protocol</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>December 2018</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">11/12</td><br />
<td style="width:300px">Ant&oacute;nio Casimiro</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="In this talk we introduce the AQUAMON project. The project is about environmental monitoring in large physical areas and in harsh conditions. This requires the use of wireless communication networks for quasi-real-time provision of monitoring data, as well as dependability concerning the quality ofthe collected monitoring data. The challenge is to ensure that these requirements are satisfied despite the harsh operaitonal conditions. The presentation will introduce the project, explain what we intend to do, what are the main challenges and how do we plan to address them.">AQUAMON: Dependable Monitoring with Wireless Sensor Networks in Water Environments</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/12</td><br />
<td>Carlos Nascimento</td><br />
<td><span style="border-bottom: dashed 1px #000" title="This presentation will present a comparative review of a set of existing wireless communication technologies that are specially targeted to support the IoT paradigm, and which may form the basis of the network layer in the AQUAMON project. The aim of this initial work performed in the scope of AQUAMON, is to understand and evaluat these technologies, such that the solution to be defined will be adequate to achieve the requirements for real-time environmental monitoring in harsh environments.">Review of wireless technology for AQUAMON: Lora, sigfox, nb-iot</span></td><br />
<td>&nbsp;</td><br />
</tr> <br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" style="background:#89B085"><br />
<tr><br />
<td style="width:100px">15/01</td><br />
<td style="width:300px">Fernando Alves</td><br />
<td style="width:600px"><span style="border-bottom: dashed 1px #000" title="Vulnerability databases (such as the NVD) are considered one of the main venues for vulnerability awareness. However, these sources only publish content that has been verified, i.e., vulnerabilities that have been confirmed by the affected software vendor and that have undergone analysis by the database management (for example, to calculate the CVSS score). On the other hand, since Open Source Intelligence encompasses information from multivariate origins, it is possible that some vulnerability data is available on the Internet before it is indexed in vulnerability databases. In this Navtalk I will present some preliminary results of a comparative study between the publishing of some vulnerabilities in OSINT and in vulnerability databases.">A comparison between vulnerability publishing in OSINT and Vulnerability Databases</span></td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>15/01</td><br />
<td>Ib&eacute;ria Medeiros</td> <br />
<td><span style="border-bottom: dashed 1px #000" title="In this talk, we present the SEAL project. The project is about the detection of vulnerabilities and implementation of software security in web applications written in different server-side languages (e.g., PHP, Hack, Java, ASP). To handle different languages, an intermediate language capable of representing server-side language aspects and secure code features is needed to be defined. In addition, tools to process this language to identify vulnerabilities are required as well as tools able to remove vulnerabilities in the source code of web applications. In the first instance, the presentation will introduce the project, its goals, what are the main challenges and the expected results. Next, we present the ongoing work related to the most main challenge.">SEAL: SEcurity progrAmming of web appLications</span></td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<br />
<!-- <br />
###########################################################<br />
############## UPCOMING PRESENTATIONS#####################<br />
########################################################### --><br />
<br />
<h2><strong>Upcoming presentations</strong></h2><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>January 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<br />
<tr><br />
<td>29/01</td><br />
<td>Fernando Ramos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>29/01</td><br />
<td>Miguel Garcia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td> <br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>February 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">19/02</td> <br />
<td style="width:300px">Ana Fidalgo</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>19/02</td> <td>Jo&atilde;o Sousa</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>March 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">12/03</td> <br />
<td style="width:300px">Pedro Gaspar</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>12/03</td> <td>Ricardo Morgado</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Andr&eacute; Oliveira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>26/03</td> <td>Nuno Dion&iacute;sio</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>April 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">09/04</td> <br />
<td style="width:300px">Adriano Serckumecka</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/04</td> <td>Tulio Ribeiro</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Miguel Moreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>30/04</td> <td>Pedro Ferreira</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>May 2019</strong></h3><br />
<table border="0" cellspacing="0" ><br />
<tr><br />
<td style="width:100px">14/05</td><br />
<td style="width:300px">Diogo Gon&ccedil;alves</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>14/05</td> <td>Vinicius Cogo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Francisco Ara&uacute;jo</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>28/05</td> <td>Miguel Matos</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>June 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">11/06</td><br />
<td style="width:300px">Eric Vial</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>11/06</td><br />
<td>Robin Vassantlal</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Jo&atilde;o Pinto</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>25/06</td><br />
<td>Tiago Correia</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>July 2019</strong></h3><br />
<table border=0 cellspacing=0 > <br />
<tr><br />
<td style="width:100px">09/07</td><br />
<td style="width:300px">-</td><br />
<td style="width:600px">&nbsp;</td><br />
<td style="width:100px">&nbsp;</td><br />
</tr><br />
<tr><br />
<td>09/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<tr><br />
<td>23/07</td><br />
<td>-</td><br />
<td>&nbsp;</td><br />
<td>&nbsp;</td><br />
</tr><br />
<br />
</table><br />
</div><br />
<br />
<br />
<!--<br />
<div style="background:#FFFFFF; border:1px solid #FFFFFF; padding:5px 10px"><br />
<h3><strong>Not Scheduled</strong></h3><br />
<table border=1 background=#DA4848 style="width:20%"> <br />
<tr><br />
<td>Bruno Louren&ccedil;o</td> <br />
</tr><br />
<br />
<tr><br />
<td>Cl&aacute;udio Martins</td> <br />
</tr><br />
<tr><br />
<td>Diogo Edgar Sousa</td> <br />
</tr><br />
<tr><br />
<td>Gon&ccedil;alo Jesus</td> <br />
</tr><br />
<tr><br />
<td>Hugo Amieira</td><br />
</tr><br />
<tr><br />
<td>Lu&iacute;z Marques</td> <br />
</tr><br />
<tr><br />
<td>Paulo Antunes</td> <br />
</tr><br />
<tr><br />
<td>Rui Azevedo</td> <br />
</tr><br />
</table><br />
</div><br />
--></div>Tribeiro