A system is said to be current-state opaque if the entrance of the system state to a set of secret states remains opaque (uncertain) to an intruder - at least until the system leaves the set of secret states. This notion ...

We consider distributed fault diagnosis in a discrete event system modeled as a nondeterministic finite automaton that is observed at multiple observation sites through distinct natural projection maps. The majority of ...

A non-deterministic finite automaton is initial-state opaque if the membership of its true initial state to a given set of secret states S remains opaque (i.e., uncertain) to an intruder who observes system activity through ...

In many emerging security applications, a property of a system, that may reveal important details about its behaviour, needs to be kept secret (opaque) to outside observers (intruders). Motivated by such applications, ...

State-based notions of opacity, such as initial-state opacity and infinite-step opacity, emerge as key properties in numerous security applications of discrete event systems. We consider systems that are modeled as partially ...

We describe and analyze the complexity of verifying the notion of infinite-step opacity in systems that are modeled as non-deterministic finite automata with partial observation on their transitions. Specifically, a system ...

Motivated by security and privacy considerations in a variety of applications of discrete event systems, we describe and analyze the computational complexity required for verifying the notion of K-step opacity for systems ...