Princeton University

School of Engineering & Applied Science

A General Formula and Second-Order Asymptotics on Secret Key Agreement

Dr. Shun Watanabe, University of Tokushima, University of Maryland
Engineering Quadrangle J323
Thursday, October 16, 2014 - 4:30pm to 5:30pm


We consider information theoretically secure secret key agreement. This problem has been well studied under the assumption that the observations by the legitimate parties are distributed according to an i.i.d. distribution. However, the i.i.d. assumption is not necessarily appropriate in practice, and it is desired to derive a general formula that can be applied for any observations. Even under the i.i.d. assumption, derivation of the second-order asymptotics is important since it provides a good insight on systems in finite blocklength regime. 
In this talk, we review some basic results on secret key agreement. Then, we introduce some new techniques for both the achievability part and the converse part. By using those techniques, we derive a general formula and the second-order asymptotics on secret key agreement. This talk is based on a joint work with Himanshu Tyagi and Masahito Hayashi.

Shun Watanabe received B.E., M.E., and Ph.D. degree from Tokyo Institute of Technology in 2005, 2007, and 2009, respectively. Since April 2009, he has been an assistant professor of the Department of Information Science and Intelligence Systems at the University of Tokushima. Since April 2013, he has also been a visiting assistant professor at the University of Maryland. His research interests include information theoretic security, network information theory,and quantum information theory.