Automated Certification of Non-Interference in Rewriting Logic

In this paper we propose a certification technique for noninterference of Java programs based on rewriting logic, a very general logical and semantic framework efficiently implemented in the high-level programming language Maude. Non–interference is a semantic program property that prevents illicit information flow to happen. Starting from a basic specification of the semantics of Java written in Maude, we develop an information–flow extension of this operational Java semantics which allows us to observe non-interference of Java programs. Then we develop in Maude an abstract, finite-state version of the information-flow operational semantics which supports finite program verification. As a by–product of the verification, a certificate of non-interference is delivered which consists of a set of (abstract) rewriting proofs that can be easily checked by the code consumer using a standard rewriting logic engine.