(joint work with Martín Abadi and Cédric Fournet)
In the analysis of security protocols, methods and tools for reasoning about protocol behaviors have been quite effective. We aim to expand the scope of those methods and tools. We focus on proving equivalences P ~ Q in which P and Q are two processes that differ only in the choice of some terms. These equivalences arise often in applications. We show how to treat them as predicates on the behaviors of a process that represents P and Q at the same time. We develop our techniques in the context of the applied pi calculus and implement them in the tool ProVerif.