Protocol Proof Checking Simplified with SMT

Abstract

We believe that recent advances in formal verification are on the verge of making formal verification a viable option for any protocol designer, assuming the designer understands the protocol well enough to explain why it works. We demonstrate this with an SMT-based proof checker developed at Intel called the Deductive Verification Framework (DVF). We show how DVF can be used to prove correct a classical, fault-tolerant, distributed protocol for consensus, and describe how a protocol expert starting from scratch, with little-to-no prior familiarity with SMT or DVF, was able to model the protocol and prove it correct in six days and nine pages.