Abstract: Trusted Computing is about guaranteeing the integrity of a remote service based on a small piece of secure hardware. Despite several solutions have been proposed, they either focus on small applications or their performance strongly depends from the service’s state size. In this DI-Smalltalk I will advance some ideas to deal with the problem of computing over a large state in a constrained environment, while still being able to deliver security guarantees that are efficiently verifiable.

About the presenter: Ph.D. student at FCUL-DI & CMU-CSD

Abstract: Secure two-party computation allows two parties to compute functions of their combined inputs, while retaining privacy of the inputs. Progress in recent years has improved up to a practical level the efficiency of this functionality. And now what? In what applications is S2PC going to find its way in the real world? In this DI-Smalltalk I will ask for ideas of practical applications of S2PC and will talk about brokered identification as a candidate context where a small S2PC can be used to solve a big privacy problem.

About the presenter: Ph.D. student at FCUL-DI and CMU-ECE

Abstract:
MapReduce is often used for critical data processing, e.g., in the context of scientific or financial simulation. However, there is evidence in the literature that there are arbitrary (or Byzantine) faults that may corrupt the results of MapReduce without being detected.

In this smalltalk I will present an (i) overview of the MapReduce framework, (ii) focus on the limitations of the framework, (iii) describe the existent related work, (iv) show a new design to make the framework able to tolerate arbitrary faults, (iv) present two modes of execution in order to improve performance, (v) and show the results of the experiments.

This is a first step in order to scale out MapReduce computation to a cloud of clouds environment.

About the presenter: PhD student

Abstract: Since Francis Crick introduced his pioneer concepts in the 50’s that molecular biologists like myself have been striving in the lab to unravel the principles and mechanisms underlying biological information. Recently, however, major breakthroughs in technology – namely ‘Next Generation Sequencing’ – have turned biology into a data intensive science, highly reliant on demanding computational approaches.

In this DI-Smalltalk I will provide an overview on these topics and current challenges. By the end, I expect the audience to have gained some insight into this brave new world, full of opportunities to apply their expert knowledge, hopefully paving the way for interdisciplinary collaborations.

About the presenter: Investigadora do Centro de Investigação BioFIG

Abstract: Raft is a consensus algorithm that is designed to be easy to understand. It’s equivalent to Paxos in fault-tolerance and performance. The difference is that it’s decomposed into relatively independent subproblems, and it cleanly addresses all major pieces needed for practical systems. In this talk I will present this algorithm and show the system model.

Slides here

About the presenter: Ph.D. student

Abstract: Communication-Centred (CC) programming has as a focus the descriptions of reliable communication protocols for distributed systems. Interestingly, there has been two main visions when specifying CC programs: An imperative vision, where the message flows are defined explicitly, and a declarative one, where such flows are described as a collection of constraints to be respected.
We will present an approach that integrates both the operational and the declarative flavours of CC programs. By relying on a (timed) concurrent constraint programming language, we show that in addition to the usual operational techniques from process calculi, a CC program can elegantly exploit logic-based reasoning techniques coming from its declarative transformation. I will discuss some details of the approach, as well as some of the challenges.

About the presenter: Postdoct at FCUL-DI

Abstract: In this Smalltalk I will talk about some of the features introduced in Java SE 7. Although version 7 was introduced in the year 2011, some of its useful features may have been overlooked by programmers that started using Java before then. My goal is to remind people of these features, with focus on the area of Networking and Operating Systems.

Slides Here

Abstract: We propose a resilience architecture for improving the security and dependability of authentication and authorization infrastructures, in particular the ones based on RADIUS and OpenID. This architecture employs intrusion- tolerant replication, trusted components and untrusted gateways to provide survivable services ensuring compatibility with standard protocols. The architecture was instantiated in two prototypes, one implementing RADIUS and another implementing OpenID. These prototypes were evaluated in fault-free executions, under faults, under attack, and in diverse computing environments. The results show that, beyond being more secure and dependable, our prototypes are capable of achieving the performance requirements of enterprise environments, such as IT infrastructures with more than 400k users.

Abstract: If you are not a solitaire cowboy while coding your masterpieces than you got to know two important tools: Git and Slack. Come to the next smalltalk and I will tell you about these tools and how they can speed up you team work and have a lot of fun at the same time.

Slides Here

Abstract: In this smalltalk, the presenter will describe the Bloom filter (BF) data structure, as well as present known use cases in big data and some existent implementations. BFs are space-efficient probabilistic data structures for membership testing (i.e., test if an element belongs or not to a large dataset).

Slides Here

About the presenter: Ph.D student at FCUL-DI