A state-based approach to noninterference

We outline an alternative approach to modeling noninterference-style security policies using a state-based model (as opposed to an event-based or i/o-based model). We believe that this approach provides a richer, more intuitive formalism for security modeling than the event-based approach and provides a link to other current research in specification and verification of concurrent and distributed systems. We describe the state-based approach for deterministic and non-deterministic systems with both transitive and intransitive security policies