Partial Order Reductions for Security Protocol Verification

In this paper we explore partial order reduction that make the task of verifying cryptographic protocols more efficient. These reduction techniques have been implemented in our tool BRUTUS. Although we have implemented several reduction techniques in our tool BRUTUS, due to space restrictions in this paper we only focus on partial order reductions. Partial order reductions have proved very useful in the domain of model checking reactive systems. These reductions are not directly applicable in our context because of additional complications caused by tracking knowledge of various agents. We present partial order reductions in the context of verifying security protocols and prove their correctness. Experimental results showing the benefits of this reduction technique are also presented.