Constraint Abstraction in Verification of Security Protocols

Abstract

This paper incorporates time constraints in the Horn logic model, and this extended model can verify Wide-Mouthed-Frog protocol quickly. It discusses relations between the constraint system and Horn model, abstracts the constraint system, and gives the proofs of some propositions and theorems. We also give the algorithm about how to compute the abstract constraint, and analyze its complexity. As a case study we discuss the verification of Wide-Mouthed-Frog protocol whose attack can be found quickly in new model. Therefore, the method in this paper is very effective in verification of time sensitive security protocols. In the future, we will use this method to verify some complex protocols, such as Kerberos protocol etc.