A Framework for the Cryptographic Verification of Java-Like Programs

We consider the problem of establishing cryptographic guarantees -- in particular, computational indistinguishability -- for Java or Java-like programs that use cryptography. For this purpose, we propose a general framework that enables existing program analysis tools that can check (standard) non-interference properties of Java programs to establish cryptographic security guarantees, even if the tools a priori cannot deal with cryptography. The approach that we take is new and combines techniques from program analysis and simulation-based security. Our framework is stated and proved for a Java-like language that comprises a rich fragment of Java. The general idea of our approach should, however, be applicable also to other practical programming languages. As a proof of concept, we use an automatic program analysis tool for checking non-interference properties of Java programs, namely the tool Joana, in order to establish computational indistinguishability for a Java program that involves clients sending encrypted messages over a network, controlled by an active adversary, to a server.