Journal Article: A new algorithm for low-deterministic security

We present a new algorithm for checking probabilistic noninterference in concurrent programs. The algorithm, named RLSOD, is based on the Low-Security Observational Determinism criterion. It utilizes program dependence graphs for concurrent programs, and is flow-sensitive, context-sensitive, object-sensitive, and optionally time-sensitive. Due to a new definition of low-equivalency for infinite traces, the algorithm avoids restrictions or soundness leaks of previous approaches. A soundness proof is provided. Flow-sensitivity turns out to be the key to precision, and avoids prohibition of useful nondeterminism. The algorithm has been implemented for full Java bytecode with unlimited threads. Precision and scalability have been experimentally validated.