Speakers Lectures Friday 22 November 2019

Gilles Brassard
Big Brother in a Quantum World

Although practised as an art and science for ages, cryptography had to wait until the mid-twentieth century before Claude Shannon gave it a strong mathematical foundation. However, Shannon's approach was rooted in his own information theory, itself inspired by the classical physics of Newton and Einstein. When quantum theory is taken into account, new vistas open up both for codemakers and codebreakers. Is this a blessing or a curse for the protection of privacy and the fight against Big Brother so central to David's mission? As we shall see, the jury is still out!
(No prior knowledge in quantum theory will be assumed)            

Professor of computer science since 1979 and Canada Research Chair at the Université de Montréal, Gilles Brassard FRS, O.C., O.Q., laid the foundations of quantum cryptography at a time when only a handful of people worldwide were interested in quantum information science. He is also among the inventors of quantum teleportation, a universally recognized pillar of the entire discipline for which Thomson Reuters has predicted that he will one day receive the Nobel Prize in Physics. Editor-in-Chief for Journal of Cryptology from 1991 until 1997, he is the author of three books that have been translated into eight languages. He is a Fellow of the Royal Society of London and the International Association for Cryptologic Research. Among his many awards, we note the NSERC Gerhard Herzberg Canada Gold Medal for Science and Engineering and the Killam Prize for natural sciences, which are the two most prestigious science recognitions in Canada. He was awarded honorary doctorates by the ETH in Zürich, the University of Ottawa and the Università della Svizzera italiana in Lugano, and made an Officer of the Order of Canada and of the Ordre national du Québec. In 2018, he became the first Canadian to receive the Wolf Prize for Physics. The following year, he received the newly created Micius Quantum Prize.
Presentation Gilles Brassard

David Chaum
Designing a Metadata Resistant Network

In his presentation, David Chaum will provide an update on Elixxir, his privacy protecting transaction platform, and Praxxis, his consensus protocol underpinning a full-stack blockchain and denominated cryptocurrency.

Elixxir was founded by David Chaum, a pioneer in cryptography and privacy-preserving technologies and widely recognized as the inventor of digital cash. His 1982 work on cryptographic "vault systems" contains the first proposal for a blockchain protocol, containing all but one element detailed 26 years later in the Bitcoin white-paper.
His company DigiCash, created the first digital currency, eCash, in 1995. eCash deployed David's breakthrough cryptographic blind signature protocol to create the world's first attempt at anonymous digital cash. He is also known for creating other fundamental innovations in cryptography like mix networks, the cMix protocol, and secure election systems. With a PhD in Computer Science from UC Berkeley, he taught at NYU Graduate School of Business and the University of California, led a number of breakthrough projects and founded the International Association for Cryptologic Research, the cryptography group at CWI, DigiCash, the Voting Systems Institute, and the Perspectiva Fund.
Presentation David Chaum

Claude Crépeau
Demonstrating That a Public Graph Can Be 3-Coloured Without Revealing Any Knowledge About How...
In this talk, we review the early days of Interactive Proofs, Interactive Arguments and other Zero-Knowledge protocols. We highlight Chaum’s contributions to this young (30 years ago) field and where it led us today. We survey current research on Argument Systems, as well as Zero-Knowledge proofs where soundness and zero-knowledge only rest on the assumption that no information can travel faster than the speed of light.

Claude Crépeau is a professor in the School of Computer Science at McGill University. Ηe was born in Montreal, Quebec, Canada, in 1962. He received a master's degree from the Université de Montréal in 1986, and obtained his Ph.D. in Computer Science from MIT in 1990, working in the field of cryptography with Prof. Silvio Micali as his Ph.D. advisor and Gilles Brassard as his M.Sc advisor. He spent two years as a Postdoctoral Fellow at Université d'Orsay, and was a CNRS researcher at École Normale Supérieure from 1992 to 1995. He was appointed associate professor at Université de Montréal in 1995, and has been a faculty member at McGill University since 1998. He was a member of the Canadian Institute for Advanced Research program on Quantum Information Processing from 2002 to 2012. He was nominated as an IACR Fellow in 2013 https://www.iacr.org/fellows/. Prof. Crépeau is mostly known for his fundamental work in zero-knowledge proof, multi-party computing, quantum cryptography, and quantum teleportation.
Presentation Claude Crépeau

Serge Fehr
Multiparty Computation: Collaborate without Compromise(ing Your Data)
Multiparty computation (MPC) provides cryptographic means that enable mutually distrustful parties to collaborate in a secure way, ensuring that individual data used for the collaboration remains private. The theoretical foundations of MPC were set in the early eighties in a sequence of pioneering work that showed general possibility results. Since then, MPC has remained a lively research topic but was long considered to be of theoretical interest only due to its large computational overhead. However, thanks to the continuous efforts in making MPC more efficient, it is now at the verge of being
practically relevant and is gradually starting to experience real world deployment. In this presentation, I explain the general goal of MPC, give some details on how it can be achieved, and discuss some potential and actual real-world applications.

Serge Fehr is a senior researcher in the Cryptology Group at CWI, and a professor of mathematics at Leiden University. He obtained his M.Sc. in mathematics from ETH Zurich (Switzerland) in 1998 and his Ph.D. in computer science from Aarhus University (Denmark) in 2003. He is a leading scientist in the area of cryptography and its connections to mathematics, in particular to algebra and number theory and to quantum information theory and quantum computing.
Serge is also a member of QuSoft, the Dutch research center for quantum software, and of AMSec, the Amsterdam Cyber Security Center. He is on the editorial board of the Journal of Cryptology and of the IEEE Transactions on Information Theory, and he is currently the co-chair of the steering committee of QCrypt, the annual conference on quantum cryptography.
Presentation Serge Fehr

Anna Lysyanskaya
1984 without Big Brother: Anonymous Credential Systems and Variations
In 1984, David Chaum wrote: "Today, individuals provide substantially the same identifying information to each organization with which they have a relationship. In a new [better] paradigm, individuals [should] provide different "pseudonyms" or alternate names to each organization. A critical advantage of systems based on such pseudonyms is that the information associated with each pseudonym can be insufficient to allow data on an individual to be linked and collected together, and thus they can prevent the formation of a dossier society reminiscent of Orwell's "1984"."

Thirty-five years later, this vision is as relevant as ever.  Luckily, we also have as many years of developments of cryptographic approaches to the 1984 problem.  In this talk, I will go over these approaches, from anonymous credentials, to anonymous electronic cash and untraceable e-tokens, to anonymous attestation, and beyond.


Anna Lysyanskaya is a Professor of Computer Science at Brown University. She received an A.B. in Computer Science and Mathematics from Smith College in 1997, and a Ph.D. in Computer Science and Electrical Engineering from MIT in 2002. She is a recipient of an NSF CAREER award and a Sloan Foundation fellowship and was included in the Technology Review Magazine's list of 35 innovators under 35 for 2007. In 2012, she was elected (and in 2015 and 2018, reelected) a Director of the International Association for Cryptologic Research.  Anna Lysyanskaya's research interests are in cryptography, theoretical computer science, and computer security. A theme of her research, inspired by David Chaum's pioneering work, is on balancing privacy with accountability, and specifically allowing users to prove that they are authorized even while not revealing any additional information about themselves.
Presentation Anna Lysyanskaya