Date: Monday, May 14, 2012
Time: 12:00pm – 1:30pm
Place: Maxwell Dworkin 119

Speaker:  Vashek Matyáš, Harvard CRCS and Masaryk University Brno, CZ

Title:  Design of privacy mechanisms for wireless sensor networks with intrusion detection

Abstract:  Wireless sensor networks often have to be protected not only against an active attacker who tries to disrupt network operations, but also against a passive attacker looking for some sensitive information like the location of a certain node or information about the movement of a tracked object. To address such issues, we can use an intrusion detection system and a privacy mechanism simultaneously. However, both of these often come with contradictory aims.  A privacy mechanism typically tries to hide a relation between various events while an intrusion detection system tries to link the events up.

This talk will present and explore some of the problems that might occur when such techniques are brought together and we also provide some ideas how these problems could be solved. Other related work on simulations (of wireless sensor networks), experiments with evolutionary algorithms for protocol design, and our attempts to provide a semi-automated framework that optimizes the configuration of an intrusion detection system in terms of detection accuracy and memory usage shall be also mentioned.

Bio:  Vashek Matyáš is a Fulbright-Masaryk Visiting Scholar at the Center for Research on Computation and Society (CRCS) at Harvard University and a Professor at the Masaryk University Brno, CZ. His research interests relate to applied cryptography and security. He worked with Microsoft Research Cambridge, University College Dublin, Ubilab at UBS AG, and was a Royal Society Postdoctoral Fellow with the Cambridge University Computer Lab. Vashek edited the Computer and Communications Security Reviews, and worked on the development of Common Criteria and with ISO/IEC JTC1 SC27.

TUESDAY, April 24, 2012

CRCS Lunch Seminar

Date: TUESDAY, April 24, 2012
Time: 11:00AM – 12:30pm
Place: Pierce Hall 100F

Speaker:  Tony Kwasnica, Penn State

Title:  Why Sellers Should Prefer Sequential Mechanisms

Abstract:

We analyze two mechanisms commonly used for selling an asset or a contract, in a setting in which bidders must incur an entry cost in order to learn how much the asset is worth to them: an English auction, and a sequential bidding process.  A theory developed by Bulow and Klemperer (2009) predicts that sellers should prefer the auction, because it generates higher average revenues, while bidders should prefer the sequential mechanism, because it generates higher average bidder profits. We compare the two mechanisms in a controlled laboratory environment, varying the entry cost, and find that, contrary to the theoretical predictions, average seller revenues tend to be the same or higher under the sequential mechanism, while average bidder profits are approximately the same.  We identify three behavioral causes that explain our result: (1) bidders do not enter the auction 100% of the time, and (2) in the sequential mechanism, bidders do not set pre-emptive bids according to the threshold strategy, and (3) the subsequent bidders tend to over-enter in response to pre-emptive bids by the first bidders.  We develop a model of noisy bidder entry decisions, related to quantal response equilibrium, and show, using maximum-likelihood parameter estimation techniques, that our model does a good job in organizing the experimental data, both, in terms of point predictions, as well as in terms of qualitative comparisons of the two mechanisms.

Joint work with Andrew Davis (Cornell), Elena Katok (PSU).

CRCS Lunch Seminar

Date: Monday, April 9, 2012
Time: 12:00pm – 1:30pm
Place: Maxwell Dworkin 119

Speaker: Anupam Datta, Carnegie Mellon University

Title: Privacy, Audit and Accountability

Abstract: Privacy has become a significant concern in modern society as personal information about individuals is increasingly collected, used, and shared, often using digital technologies, by a wide range of organizations. To mitigate privacy concerns, organizations are required to respect privacy laws in regulated sectors (e.g., HIPAA in healthcare, GLBA in financial sector) and to adhere to self-declared privacy policies in self-regulated sectors (e.g., privacy policies of companies such as Google and Facebook in Web services). We investigate the possibility of formalizing and enforcing such practical privacy policies using computational techniques. We formalize privacy policies that prescribe and proscribe *flows* of personal information as well as those that place restrictions on the *purposes* for which a governed entity may use personal information. Recognizing that traditional preventive access control and information flow control mechanisms are inadequate for enforcing such privacy policies, we develop principled audit and accountability mechanisms with provable properties that seek to encourage policy-compliant behavior by detecting policy violations, assigning blame and punishing violators.
We apply these techniques to several US privacy laws and organizational privacy policies, in particular, producing the first complete logical specification and audit of all disclosure-related clauses of the HIPAA Privacy Rule.

Short Bio: Anupam Datta is an Assistant Research Professor at Carnegie Mellon University where he has appointments in CyLab, Electrical & Computer Engineering, and (by courtesy) Computer Science Departments. His research focuses on the scientific foundations of security and privacy. Dr. Datta has authored a book, over 40 publications, and presented numerous seminars on programming language, logical, and algorithmic methods for privacy, software system security, and cryptographic protocol analysis and design. He serves on the Steering Committee of the IEEE Computer Security Foundations Symposium, and has served as Program and General Chair of several meetings on security foundations and on the program committees of top security and privacy conferences. He participates in the NSF TRUST center on security and the HHS SHARPS center on healthcare security and privacy. Dr. Datta obtained PhD and MS degrees from Stanford University and a BTech from IIT Kharagpur, all in Computer Science.

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CRCS Lunch Seminar

Date: Monday, April 2, 2012
Time: 12:00pm – 1:30pm
Place: Maxwell Dworkin 119

Speaker: Susan Landau, Visiting Scholar,  Computer Science, Harvard University

Title: PBS Great Decisions: Cybersecurity
http://www.fpa.org/features/index.cfm?act=feature amp;announcement_id=125

Abstract: This year’s Great Decisions program http://www.fpa.org/great_decisions/ has produced a program on cybersecurity, focusing on the international issues:

The securitization of cyberspace has caused a sea change for both governments and the private sector, faced with new threats, new battlegrounds and new opportunities. Faced with challenges such as international cybercrime and authoritarian control of networks, how will the U.S. and its democratic allies approach the cyber frontier? How does this new domain figure in U.S. strategic interests?

Computer scientists have one sense of what the cybersecurity problem is, Washington has a somewhat different one. This talk is the half-hour program (to be aired on WGBH March 16) followed by a Q&A with Susan Landau, who is visiting computer science this year.

Short Bio: Susan Landau is currently a Visiting Scholar in the Computer Science Department at Harvard University. She was previously a Distinguished Engineer at Sun Microsystems, and held faculty positions at the University of Massachusetts and Wesleyan University. She has worked on security, cryptography, and policy, including surveillance and digital-rights management issues. Landau is the author of “Surveillance or Security? The Risks Posed by New Wiretapping Technologies” (MIT Press, 2011), coauthor, with Whitfield Diffie, of “Privacy on the Line: the Politics of Wiretapping and Encryption” (MIT Press, 1998; rev. 2007), and the author of numerous computer science and public policy papers, as well as op-eds on cybersecurity and encryption policy. She is a member of the National Research Council Computer Science and Telecommunications Board and serves on the advisory committee for the National Science Foundation’s Directorate for Computer and Information Science and Engineering. Landau was a fellow at the Radcliffe Institute for Advanced Study, is a recipient of the 2008 Women of Vision Social Impact Award, and is a fellow of both the AAAS and the ACM. She received her BA from Princeton, her MS from Cornell, and her PhD from MIT.

Date: Monday, February 27, 2012
Time: 12:00pm – 1:30pm
Place: Maxwell Dworkin 119

Speaker: Adelheid Voskuhl, Department of History of Science at Harvard University

Title: Engineering and crisis: technical and social elites in Germany and the US during the “Second Industrial Revolution,” 1890-1925

Abstract: German engineers constituted themselves as a newly emerging professional group in the two decades before the First World War and aimed to establish themselves also as a new social elite. They encountered intense competition with existing elites, however, that were trained in philosophy, history, theology, and law, and that had emerged in Germany as a distinguished civil-servant class earlier in the 19th century. One strategy for engineers to “catch up” with these existing elites was to mimic their social and intellectual behaviors and engage in “philosophy of technology,” that is, to start reading and writing philosophical texts in associations and periodicals that they established specifically for this purpose. They pondered questions about the relationship between industrialism and government, technocratic and democratic political systems, and ethical obligations of technological experts in fast-growing industrial societies. German engineers also turned across the Atlantic Ocean, to their American colleagues and peers, to seek advice and institutional and intellectual support on matters of gaining social respect as a new professional group. This German-American engineering cooperation was also formally constituted in associations and periodicals, and started out during the big world’s fairs in Philadephia and Chicago (in 1888 and 1893). My talk traces this cross-Atlantic exchange between 2 distinct engineering cultures, and corresponding philosophical cultures, and their understandings of the political, military, and social crises of the emerging industrial nation-states in the first decades of the twentieth century.

Short bio:
Adelheid Voskuhl is an associate professor in the Department of History of Science at Harvard University. Her teaching and research interests include the History and Philosophy of Technology from the early modern to the modern period, Modern European History, and History and Ethics of Engineering. She received her PhD in Science and Technology Studies from Cornell University in 2007, and holds graduate degrees in History and Philosophy of Science from Cambridge University and in Physics from Carl-von-Ossietzky-Universität Oldenburg. Her first book _Mechanics of Sentiment: Androids, Industrialism, and Selfhood in Eighteenth-Century Europe_ is slated for release in early 2013 with Chicago University Press.

Date: Monday, November 28, 2011
Time: 12:15pm – 1:45pm
Place: Maxwell Dworkin 119

Speaker: Yuval Emek, ETH Zurich

Title: Mechanisms for Multi-Level Marketing

Abstract: Multi-level marketing is a marketing approach that motivates its participants to promote a certain product among their friends. The popularity of this approach increases due to the accessibility of modern social networks, however, it existed in one form or the other long before the Internet age began (the infamous Pyramid scheme that dates back at least a century is in fact a special case of multi-level marketing). In this talk we lay foundations for the study of reward mechanisms in multi-level marketing within social networks. We provide a set of desired properties for such mechanisms and show that they are uniquely satisfied by geometric reward mechanisms. The resilience of mechanisms to false-name manipulations is also considered; while geometric reward mechanisms fail against such manipulations, we exhibit other mechanisms which are false-name-proof. The talk will be self-contained.

Based on a joint work with Ron Karidi, Moshe Tennenholtz, and Aviv Zohar.

Short bio: Yuval Emek graduated summa cum laude from the Technion (Israel Institute of Technology) with a bachelor degree in computer science and completed his master studies and Ph.D. in computer science at the Weizmann Institute. Following that, he spent one year as a post-doc at Tel Aviv University and another year in Microsoft. He currently holds a post-doc position at ETH Zurich, Switzerland. In his scientific work, Yuval studies various aspects of complex distributed systems with an emphasis on the interaction between self-interested parties.

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Date: Monday, November 14, 2011
Time: 12:15pm – 1:45pm
Place: Maxwell Dworkin 119

Speaker: Michal Feldman, Harvard CRCS and Hebrew University of Jerusalem

Title: Providing performance guarantees without assuming rationality of others

Abstract: We study performance guarantees that can be provided to decision makers in a game, without making any assumptions on the rationality of the other players. The first setting is a symmetric two-person repeated game, where one player — our decision maker — never observes a single payoff (but observes the opponent’s play), while her opponent has full knowledge of the game. Naturally, the decision maker should attempt to mimic the opponent’s play. However, one has to be careful about how one mimics opponents who may know that they are being mimicked. As we show, a good copycat can reap tremendous rewards without ever observing a single payoff, while a poor copycat may perform worse than making random decisions. We then extend the model to a multi-player setting, in which only a single player is informed. We show that a {\em master} who controls the uninformed players can guarantee for each one of them (simultaneously) a similar performance to that of the informed player, even if the latter gets to choose the payoff matrix after the fact. Key to our analysis is the study of multi-player games,and the guarantees that a master player that plays on behalf of a set of players can offer them, without making any assumptions on the rationality of the other players.

Based on joint work with Yossi Azar, Uri Feige, Adam Kalai and Moshe Tennenholtz.

Short bio: Michal Feldman is an associate Professor at the Hebrew University of Jerusalem. She received her Ph.D in 2005 from the University of California at Berkeley. Following a postdoc at the Hebrew University and at Tel-Aviv University, she joined the faculty of the School of Business Administration at the Hebrew University (in 2007). Her research focuses on the intersection of game theory, computer science and microeconomics, a field often termed “Algorithmic Game Theory”. She has been recently awarded a Marie Curie grant, and is currently a visiting scholar at the Center for Research on Computation and Society (CRCS) at Harvard University.
Website: http://pluto.huji.ac.il/~mfeldman/

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Date: Monday, November 7, 2011
Time: 12:15pm – 1:45pm
Place: Maxwell Dworkin 119

Speaker: Carla Gomes, Cornell University and Radcliffe Advanced Study Institute

Title: Computational Sustainability:
Computational Methods for a Sustainable Environment, Economy, and Society

Abstract: Computational sustainability is a new interdisciplinary research field with the overall goal of developing computational models, methods, and tools to help manage the balance between environmental, economic, and societal needs for sustainable development. The notion of sustainable development – development that meets the needs of the present without compromising the ability of future generations to meet their needs – was introduced in Our Common Future, the seminal report of the United Nations World Commission on Environment and Development, published in 1987. In this talk I will provide an overview of computational sustainability, with examples ranging from wildlife conservation and biodiversity, to poverty mitigation, to material discovery for fuel cell technology. I will highlight overarching computational challenges at the intersection of constraint reasoning and inference, optimization, machine learning, and dynamical systems. Finally I will discuss the need for a new approach that views computational sustainability problems as “natural” phenomena, amenable to a scientific methodology, in which principled experimentation, to explore problem parameter spaces and hidden problem structure, plays as prominent a role as formal analysis.

Bio:Carla Gomes is a professor of computer science at Cornell University, with joint appointments in the Department of Computer Science, Department of Information Science, and the Dyson School of Applied Economics and Management. Gomes is currently a fellow at the Radcliffe Advanced Study Institute at Harvard University (2011-2012).

Gomes’s research has covered several themes in artificial intelligence and computer science, from the integration of constraint reasoning, operations research, and machine learning techniques for solving large-scale constraint reasoning and optimization problems, to the use of randomization techniques to improve the performance of exact search methods, algorithm portfolios, multi-agent systems, and game play. Recently, Gomes has become immersed in the establishment of computational sustainability, a new interdisciplinary field that aims to develop computational methods to help balance environmental, economic, and societal needs to support a sustainable future. Gomes has started a number of research projects in biodiversity conservation, poverty mapping, the design of “smart” controls for electric cars, and pattern identification for material discovery (e.g., for fuel cell technology). While at Radcliffe Gomes will write about computational sustainability and look for new collaborations with fellows and other Harvard researchers to address challenges in computational sustainability.

Gomes obtained a PhD in computer science in the area of artificial intelligence and operations research from the University of Edinburgh. She also holds an M.Sc. in applied mathematics from the Technical University of Lisbon. Gomes is the lead principal investigator of an award from the National Science Foundation’s Expeditions in Computing program, the director of the newly established Institute for Computational Sustainability at Cornell, and a fellow of the Association for the Advancement of Artificial Intelligence.

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Date: THURSDAY, November 3, 2011
Time: 2:30pm – 4:00pm
Place:  Maxwell Dworkin 119

Speaker: Toby Walsh, NICTA and UNSW

Title: Electing the Doge

Abstract: Between 1268 and 1797, the Venetian Republic used a complicated voting system that appears designed to resist manipulation. In this talk, I study a family of voting rules inspired by this election system, which I call lot-based voting rules. Such rules have two steps: in the first step, some subset of voters are selected by a lottery, then in the second round (the runoff), these voters alone select the winner. I discuss some normative properties of such lot-based voting rules.

Joint work with Lirong Xia (Harvard).

Bio: Toby Walsh is Research Group Leader at NICTA. He is adjunct Professor at the Department of Computer Science and Engineering at the University of New South Wales, external Professor of the Department of Information Science at Uppsala University and an honorary fellow of the School of Informatics at Edinburgh University.

He is Editor-in-Chief of the Journal of Artificial Intelligence Research, and was previously Editor-in-Chief of AI Communications. He is on the editorial board of the Journal of Automated Reasoning and the Constraints journal. He has been elected a fellow of both the Association for the Advancement of Artificial Intelligence and the European Coordinating Committee for AI in recognition of his research and service to the community. He has been Secretary of the Association for Constraint Programming (ACP) and is Editor of CP News, the newsletter of the ACP. He is one of the Editors of the Handbook for Constraint Programming, and the Handbook for Satisfiability.

He was Program Chair of the Constraint Programming Conference in 2001, Conference Chair of the International Joint Conference on Automated Reasoning in 2004, Program and Conference Chair of the Satisfiability Conference in 2005, and Conference Chair of the Constraint Programming Conference in 2008. He will be Program Chair of the International Joint Conference on AI in 2011.

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Date: Monday, October 24, 2011
Time: 12:15pm – 1:45pm
Place: Maxwell Dworkin 119

Speaker: Lirong Xia, Harvard CRCS

Title: Computational Voting Theory: Game-Theoretic and Combinatorial Aspects

Abstract: For at least two thousand years, voting has been used as one of the most effective ways to aggregate people’s ordinal preferences. In the last 50 years, the rapid development of Computer Science has revolutionize every aspect of the world, including voting. This motivates us to study (1) conceptually, how computational thinking changes the traditional theory of voting, and (2) methodologically, how to better use voting for preference/information aggregation with the help of Computer Science.

This talk is an overview of my dissertation work, which seeks to investigate and foster the interplay between Computer Science and Voting Theory. I will discuss two specific research directions pursued in my Ph.D. work, one for each question asked above. The first focuses on investigating how computational thinking affects the game-theoretic aspects of voting. More precisely, I will discuss the rationale and possibility of using computational complexity to protect voting from a type of strategic behavior of the voters, called manipulation. The second studies a voting setting called Combinatorial Voting, where the set of alternatives is exponentially large and has a combinatorial structure. I will focus on the design and analysis of novel voting rules for combinatorial voting that balance computational efficiency and the expressivity of the voting language, in light of some recent developments in Artificial Intelligence.

Short bio: Lirong Xia is a postdoctoral fellow at the Center for Research on Computation and Society at Harvard University. He got a Ph.D. in Computer Science in 2011 and an M.A. in Economics in 2010, both from Duke University. His research focuses on the intersection of computer science and microeconomics, in particular computational social choice, game theory, and mechanism design.

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