Using interpolation for the verification of security protocols

Abstract

Interpolation has been successfully applied in formal methods for model checking and test-case generation for sequential programs. Security protocols, however, exhibit such idiosyncrasies that make them unsuitable to the direct application of such methods. In this paper, we address this problem and present an interpolation-based method for security protocol verification. Our method starts from a formal protocol specification and combines Craig interpolation, symbolic execution and the standard Dolev-Yao intruder model to search for possible attacks on the protocol. Interpolants are generated as a response to search failure in order to prune possible useless traces and speed up the exploration. We illustrate our method by means of a concrete example and discuss the results obtained by using a prototype implementation. © 2013 Springer-Verlag.