Model Checking CTLK Based on Knowledge-Oriented Petri Nets

We define Knowledge-oriented Petri Nets (KPN) to model and analyze multi-agent systems (MAS) especially from the perspective of privacy and security. A KPN is a special Petri net in which some places are used to represent knowledges. Consequently, KPN can formally represent not only the interaction/collaboration process of multiple agents but also their epistemic evolutions. These epistemic evolutions are closely related with the privacy and security of MAS. For those requirements of privacy or security, we use Computation Tree Logic of Knowledge (CTLK) to specify them. We define the similar reachability graphs of KPN and then construct the equivalence classes of knowledges for each agent. Based on them, we design the model checking algorithms to verify CTLK formulas efficiently. Examples of privacy protocols illustrate the usefulness of our model and method.