Abstract. A number of current automated protocol verification tools are based on abstract interpretation techniques and other over-approximations of the set of reachable states or traces. The protocol models that these tools employ are shaped by the needs of automated verification and require subtle assumptions. Also, a complex verification tool may suffer from implementation bugs so that in the worst case the tool could accept some incorrect protocols as being correct. These risks of errors are also present, but considerably smaller, when using an LCF-style theorem prover like Isabelle. The interactive security proof, however, requires a lot of expertise and time. We combine the advantages of both worlds by using the representation of the over-approximated search space computed by the automated tools as a "proof idea" in Isabelle. Thus, we devise proof tactics for Isabelle that generate the correctness proof of the protocol from the output of the automated tools. In the worst case, these tactics fail to construct a proof, namely when the representation of the search space is for some reason incorrect. However, when they succeed, the correctness only relies on the basic model and the Isabelle core.
The second REF used the theorem prover Isabelle and computed a fixpoint of an abstraction of the transition relation of the protocol of interest -this fixpoint over-approximates the set of reachable states of the protocol.
Integrating Automated and Interactive Protocol Verification
Formal Aspects in Security and Trust
Computer Science