Using Backward Strategy to the Needham-Schroeder Public Key Protocol Verification

Abstract

When dealing with secure distributed systems it is essential that entities (principals, persons, hosts, computers, etc.) are able to prove their identities to each other. The process of proving the identity is called entity authentication. Cryptographic protocols are very good tools to achieve this goal. These protocols are precisely defined sequences of communication and computation steps that use some mechanism such as encryption and decryption. In this paper we present applying a new fast method of verification of cryptographic authentication protocols to verification of the Needham-Schroeder Public Key Authentication Protocol. We present a verification algorithm, its implementation and some experimental results. Our method is a kind of model checking. To decrease the number of states in the space, which describe executions of authentication protocols in real net, we use a partial order reduction. For the verification of correctness property we apply a backward induction method.