An approach to information security in distributed systems

Information flow control mechanisms detect and prevent illegal transfers of information within a computer system. In this paper, we give an overview of a programming language based approach to information flow control in a system of communicating processes. The language chosen to present the approach is CSP. We give the security semantics of CSP and show, with the aid of examples, how the semantics can be used to conduct both manual and automated security proofs of application programs.