Petri Nets With Persistence

Persistence of information is common in modern computer systems. This paper describes how to extend Petri nets, a traditional model of concurrent and distributed computations, to take account of conditions that are persistent. We found use for this kind of nets in modelling untrustworthy networks on which messages are exchanged according to a security protocol. The paper explains a construction where persistent conditions are unfolded and a basic net is recovered. Conditions are given under which the unfolded net exhibits the same finite behaviours as the original net with persistence.