Games, Norms and Strategic Notions in Information Flow Security

Abstract

One of the concerns in the theory of computer security has been the question of what information an adversary is able to deduce about the secrets that a system is intended to maintain. Giving precise definitions of information flow security has proved to be a subtle matter. Some of the definitions that have been developed make explicit reference to strategic behaviour of the adversary. We present a perspective on these aspects of information security from epistemic logic and the theory of synthesis from logical specifications, and describe some recent results on the computational complexity of definitions of information flow security. Results concerning several types of games are drawn upon in the proofs of these complexity results. We also consider a normative aspect, viz, the use in implementations of access control permission policies to enforce an information flow security policy.

Work supported by Australian Research Council Discovery Grant DP1097203.