Abstract

The aim of this paper is to present a methodology for verifying cryptographic protocols by means of NuSMV, a symbolic model checker. We illustrate this approach by describing our analysis of the basic version of Kerberos, a widely used authentication protocol. The most innovative feature of our methodology is constituted by formal representation of security requirements. Indeed, we propose an extension of correspondence property, so far used only for authentication, to other requirements, as secrecy and integrity. This generalization leads to a unifying view of basic security requirements. The adequacy of our analysis is proved by nding an unpublished attack on Kerberos that may lead to serious consequences on the security of the systems that adopt it. 1

Citations