SOFTWARE EXPLOITATION: HARDWARE IS THE NEW BLACK (Cristiano Giuffrida, Vrije Universiteit Amsterdam)
3/3/2020
What would the world be like if software had no bugs? Software systems would be impenetrable and our data shielded from prying eyes? Not quite. In this talk, I will present evidence that reliable attacks targeting even "perfect" software are a realistic threat. Such attacks exploit properties of modern hardware such as glitches (e.g., Rowhammer) and side channels (e.g., deduplication) to completely subvert a system, even in absence of software or configuration bugs. To substantiate this claim, I will illustrate practical attacks in real-world systems settings, such as browsers, clouds, and mobile.
The implications of these attacks are worrisome. Even bug-free (say formally verified) software can be successfully targeted by a relatively low-effort attacker. Moreover, state-of-the-art security defenses, which have proven useful to raise the bar against traditional software exploitation techniques, are completely ineffective against such attacks. It is time to revisit our assumptions on realistic adversarial models and investigate defenses that consider threats in the entire hardware/software stack. Pandora's box has been opened.
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QUANTUM SUPREMACY: STATUS AND PERSPECTIVES (Fabio Sciarrino, Sapienza)
17/02/2020
We will review the recent advances achieved by Google team for the first demonstration of “quantum supremacy”, namely the regime in which a quantum system is able to outperform any classical hardware for a given computational task, even if not solving yet any useful problem. We will discuss the worldwide status and the perspectives of this research domain.
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COST SHARING OVER COMBINATORIAL DOMAINS (Georgios Birmpas, University of Oxford)
30/01/2020
We study mechanism design for combinatorial cost sharing. Imagine that multiple items or services are available to be shared among a set of interested agents. The outcome of a mechanism in this setting consists of an assignment, determining for each item the set of players who are granted service, together with respective payments. Although there are several works studying specialized versions of such problems, there has been almost no progress for general combinatorial cost sharing domains until recently \cite{DobzinskiO17}. The main goal of our work is to further understand this interplay in terms of budget balance and social cost approximation. Towards this, we provide a refinement of cross-monotonicity (trace-monotonicity) that is applicable to iterative mechanisms. The trace here refers to the order in which players become finalized. On top of this, we also provide two parameterizations of cost functions which capture the behavior of their average cost-shares. Based on our trace-monotonicity property, we design a scheme of ascending cost sharing mechanisms which is applicable to the combinatorial cost sharing setting with symmetric submodular valuations. Using our first cost function we identify conditions under which our mechanism is weakly group-strategyproof, O(1)-budget-balanced and O(logn)-approximate with respect to the social cost. Finally, we consider general valuation functions and exploit our second parameterization to derive a more fine-grained analysis of the Sequential Mechanism introduced by Moulin. This mechanism is budget balanced by construction, but in general only guarantees a poor social cost approximation of n. We identify conditions under which the mechanism achieves improved social cost approximation guarantees.
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BUILD, RUN, SURVIVE: HOW TO DESIGN EFFICIENT SYSTEMS THAT CAN WITHSTAND ADVERSARIAL SETTINGS (Leonardo Querzoni, Sapienza)
24/01/2020
The design of modern computing systems is commonly characterized by a large degree of complexity that stems from several concurrent factors. Design requirements impose several constraints that are hard to satisfy within a single solution: the system must handle fast data, in an efficient fashion, with fluctuating workloads, etc. Furthermore, such systems are sometimes expected to work in adversarial settings where malicious users may try to subvert their intended behavior. The plethora of open problems that stem from this complexity make system design an extremely interesting research field.
In this talk we will make a short stroll on some interesting problems in this field and discuss some of the contributions we provided in the last ten years. In particular we will first focus on the design of systems able to compute on fast-data, highlighting those contribution that had a larger impact on the research community. In the second part of the talk we will move our focus in the field of cybersecurity.
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TWO QUANTITATIVE STUDIES CONCERNING VOTING SYSTEMS (Allan Borodin, University of Toronto)
12/12/2019
There is a current societal interest in social choice theory (e.g. voting systems) motivated at least in part by the divisiveness apparent in many countries. Can computer science and AI bring any insight into some of the more prominent issues?
More specifically, recent elections in the US and Canada (and elsewhere) have brought to prominence a couple of issues, Gerrymamdering and the role of primaries in voting. (Voting goes beyond political elections but political elections are the most newsworthy.)
As one can imagine, there are complex modeling and computational issues when dealing with large social and political systems.
We have some preliminary but we think interesting insights into gerrymandering (strategic design of electoral districts) and primary systems. I will briefly talk about a work at IJCAI 2018 on gerrymandering and how the ``power of gerrymadering'' relates to the degree of urbanization. I will mainly talk about the issue of primaries vs direct elections as our work here is a blend of both theory and experimental work. Here is the basic question: What is the impact on the ``quality'' of our chosen leaders by having primaries where each party has its own election to choose their candidate for the general election? Does this tend to result in more extreme candidates? In a paper at AAAI 2019 paper on primaries, we conduct the first quantitative study of primary vs direct elections.
Joint work with Omer Lev, Nisarg Shah and Tyrone Strangway
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PROSPETTIVE ETICHE DELL’INTELLIGENZA ARTIFICIALE: SFIDE E SVOLTE (Piergiorgio Donatelli, Sapienza)
16/12/2019
Lo sviluppo della AI e della robotica può costituire non solo una nuova sfida per l’etica ma anche una svolta analoga a quella registrata con la bioetica negli anni Settanta. L’interazione sempre più fitta con agenti artificiali trasforma lo sfondo delle attività umane dotate di valore e richiede un ripensamento della tradizione etica che mette al centro i progetti autocreativi degli esseri umani. I concetti di autonomia, libertà, biografia si trasformano: saranno messi a repentaglio o troveranno nuove fertili applicazioni alla luce delle scelte tecnologiche degli umani.
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GRAPH CLUSTERING WITH NOISY QUERIES AND MOTIFS (Charalampos Tsourakakis, Boston University and Harvard)
9/12/2019
Graph clustering is a fundamental problem in graph mining with important applications ranging from social networks analysis and entity resolution to computer vision and semi-supervised learning. In this talk I will discuss two novel variations of graph clustering. In the first part of the talk I will discuss the following clustering problem: there exist two latent clusters, and we are allowed to query any pair of nodes whether they belong to the same cluster or not, but the answer to the query is corrupted with some probability less than 1/2. Can we recover the clusters with high probability and what is the minimum number of queries needed? I will present two state-of-the-art algorithms and a closely related application on predicting signs in online social networks. Our results improve recent results by Mazumdar and Saha [NIPS’17]. In the second part of the talk, I will discuss how to exploit motifs to uncover communities. Specifically, I will introduce the concept of motif-expanders that serves as the basis for motif-based clustering. I will present efficient algorithms and a well-performing heuristic that outperforms some of the most popular graph clustering tools. I will conclude with some experimental results that show the effectiveness of our methods to multiple applications in machine learning and graph mining.
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COMMUNICATIONS AT THE SPEED OF LIGHT (Jose-Victor Rodriguez, Universidad Politécnica de Cartagena, Spain)
10/12/2019
More than fifty years have passed since the development of optical fibers by Charles Kao in 1965. Such means of signal transmission represents one of the greatest technological advances that have been carried out in recent years. Optical fibers -which are the thickness of a human hair- are capable of guiding light so that a huge amount of information can be transmitted to very high distances, in addition to offering alternative applications that include, among others, their use in the medical, industrial or decorative fields.
In this talk, different aspects regarding the nature of light as well as the fundamentals of optical fibers will be addressed. This way, with the help of a series of visual demonstrations which will be performed through different gadgets such as laser emitters, flashlights, chromatic discs, holograms, Newton's prisms, transparent fibers, and many others, the underlying science of optical fibers will be reviewed while at the same time contemplating illustrative light-based experiments.
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COMMUNICATIONS AT THE SPEED OF LIGHT (Jose-Victor Rodriguez, Universidad Politécnica de Cartagena, Spain)
10/12/2019
More than fifty years have passed since the development of optical fibers by Charles Kao in 1965. Such means of signal transmission represents one of the greatest technological advances that have been carried out in recent years. Optical fibers -which are the thickness of a human hair- are capable of guiding light so that a huge amount of information can be transmitted to very high distances, in addition to offering alternative applications that include, among others, their use in the medical, industrial or decorative fields.
In this talk, different aspects regarding the nature of light as well as the fundamentals of optical fibers will be addressed. This way, with the help of a series of visual demonstrations which will be performed through different gadgets such as laser emitters, flashlights, chromatic discs, holograms, Newton's prisms, transparent fibers, and many others, the underlying science of optical fibers will be reviewed while at the same time contemplating illustrative light-based experiments.
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A QUANTITATIVE STUDY OF VULNERABILITIES IN THE MEDICAL INTERNET OF THINGS (Hervé Debar, Telecom SudParis, France)
18/11/2019
Medical objects, small or large, increasingly rely on digital technologies to monitor patients or deliver care. They form a part of our digital critical infrastructure, that can be significantly impacted by cyber attacks. For example, the Wannacry ransomware shut down hospitals in Europe for hours, even days. This presentation will analyze recent vulnerabilities that have affected medical objects, and present findings related to the characteristics of these vulnerabilities. It will then use these findings to propose ideas for improved cybersecurity in the medical IoT.
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