Static Semantics of Secret Channel Abstractions

The secret π-calculus extends the π-calculus by adding an hide operator that permits to declare channels as secret. The main aim is confidentiality, which is gained by restricting the access of the object of the communication. Communication channels protected by hide are more secure since they have static scope and do not allow the context’s interaction, and can be implemented as dedicated channels. In this paper, we present static semantics of secret channel abstractions by introducing a type system that considers two type modalities for channels (scope): static and dynamic. We show that secret π-calculus channels protected by hide can be represented in the π-calculus by prescribing a static type modality. We illustrate the feasibility of our approach by introducing a security API for message-passing communication which works for a standard (π-calculus) middleware while featuring secret channels. Interestingly, we just require the programmer to declare which channels are meant to be secret, leaving the burden of managing the security type abstractions to the API compiler.