SPEC: an equivalence checker for security protocols

SPEC is an automated equivalence checker for security protocols specified in the spi-calculus, an extension of the pi-calculus with cryptographic primitives. The notion of equivalence considered is a variant of bisimulation, called open bisimulation, that identifies processes indistinguishable when executed in any context. SPEC produces compact and independently checkable bisimulations that are useful for automating the process of producing proof-certificates for security protocols. This paper gives an overview of SPEC and discusses techniques to reduce the size of bisimulations, utilising up-to techniques developed for the spi-calculus. SPEC is implemented in the Bedwyr logic programming language that we demonstrate can be adapted to tackle further protocol analysis problems not limited to bisimulation checking.