Weakening the Dolev-Yao model through probability

Abstract

The Dolev-Yao model has been widely used in protocol verification and has been implemented in many protocol verifiers. There are strong assumptions underlying this model, such as perfect cryptography: the aim of the present work is to propose an approach to weaken this hypothesis, by means of probabilistic considerations on the strength of cryptographic functions. Such an approach may effectively be implemented in actual protocol verifiers. The Yahalom protocol is used as an easy example to show this approach.