Typed ψ-calculi

A large variety of process calculi extend the pi-calculus with more general notions of messages. Bengtson et al. have shown that many of these pi-like calculi can be expressed as so-called psi-calculi. In this paper, we describe a simple type system for psi-calculi. The type system satisfies a subject reduction property and a general notion of channel safety. A number of existing systems are shown to be instances of our system, and other, new type systems can also be obtained. We first present a new type system for the calculus of explicit fusions by Wischik and Gardner, then one for the distributed pi-calculus of Hennessy and Riely and finally show how existing type systems for secrecy and authenticity in the spi calculus can be represented and shown to be safe.