James R. and Shirley A. Kliegel Lecture in Engineering and Applied Science
Monday November 15, 2004
4:00 PM
Beckman Institute auditorium

Is a Mathematical Theory of Cryptography Possible?
James L. Massey, ETH Zurich

Description/Abstract:
We consider the question of whether a "mathematical theory of cryptography", akin to Shannon's celebrated "mathematical theory of communication", is possible and, if so, how far we are along the path to such a theory. We argue that the essential first step is to formulate a mathematical model of a cryptographic system with precise definitions and axioms from which theorems can be proved. We argue also that for such a theory to have practical impact there must be widespread agreement that the model adequately describes real-world cryptographic systems and scenarios. Numerous examples will be used and will lead to the inescapable conclusion that, while we may have an adequate "mathematical theory of cryptography" for unconditional security, we are very, very far from possessing such a theory for the more pertinent case of computational security.