CS Department Seminar: Prof. Rei Safavi-Naini (University of Calgary), Secure Communication against All-powerful Adversaries

Thursday, May 1, 2014 ( 2:00 pm to 3:00 pm )

Location: Babbio Center 321

Computational cryptography assumes the adversary is computationally bounded and bases security on assumptions about the hardness of mathematical problems. With such assumptions elegant solutions to important security problems such as digital signature and secure communication without a prior shared key can be found.

With massive growth in computing power, emergence of cloud computing and availability of massive computational resources at one's fingertips, a burgeoning question is, what will remain from security if one cannot assume that the adversary's computational power is limited? Or, the new developments in algorithms invalidate assumptions that have been used as the basis of security.

Information theoretic cryptography assumes computationally unlimited adversaries, and bases security on assumptions about the inaccessibility of part of the state of the physical system, hence sometimes referred to as physical assumptions. In this talk I consider the problem of securing message transmission when Alice and Bob *do not have a shared key*, assuming a computationally unlimited adversary. I outline two reasonable types of physical assumptions that can be used to construct secure protocols for message transmission.

In many existing scenarios, we may not know the algorithmic power of our opponent. We do not know secret algorithmic advances which are not published, and further, we do not know how much computing powers certain organizations possess. In such cases, we say the opponent of the system is an ``Ueber Powerful'' adversary, and for simplicity allow the adversary to be all-powerful (i.e., assuming any computation is doable for free). In presence of such adversaries, we cannot rely on hard problems for providing security (since solutions are for free).

Rei Safavi-Naini is the AITF Strategic Research Chair in Information Security and the Director of Institute for Information Security, Privacy and Information Assurance, at the University of Calgary in Canada. Before joining the University of Calgary in 2007, she was a Professor of Computer Science and the Director of Telecommunication and Information Technology Research Institute (TITR) of the University of Wollongong in Australia.

She is an Associated Editor of IEEE Transactions on Dependable and Secure
Computing, IET Information Security and Journal of Mathematical Cryptology, and has been a past Associate Editor of IEEE Transaction on Information Theory, and ACM Transactions on Information and System Security. She has been the program chair/co-chair of Asiacrypt 1994, ASIACCS 2009, ICITS 2008, SAC 2009, Information Hiding 2010, Crypto 2012, ACNS2013, and Financial Cryptography 2014, and has served on the program committee of many conferences in cryptography and security, including Eurocrypt, ACM CCS, and ESORICS.

She received her PhD in coding theory from University of Waterloo in Canada. Her research interest is in theory and practice of information security. She has (co)authored over 280 refereed papers in the areas of cryptography, communications security, identification and authentication, and secure content distribution systems.

For additional information please contact:
Prof. Susanne Wetzel