Opacity Enforcing Supervisory Control Using Nondeterministic Supervisors

In this article, we investigate the enforcement of opacity via supervisory control in context discrete-event systems. A system is said to be opaque if intruder, which modeled as a passive observer, can never infer confidently that at secret state. The design objective synthesize supervisor such closed-loop even when policy publicly known. propose new approach for enforcing using nondeterministic supervisors. decision mechanism provides a set decisions each instant, and randomly picks specific from actually plant. Compared with standard deterministic mechanism, enhance plausible deniability controlled online random realization cannot implicitly inferred policy. We provide sound complete algorithm synthesizing opacity-enforcing supervisor. Furthermore, show supervisors are strictly more powerful than sense there may exist enforce opacity.