Building a stateful reference monitor with coloured petri nets

The need for collaboration and information sharing has been recently growing dramatically with the convergence of outsourcing and off shoring, the increasing need to cut costs through cooperative agreements between partners as well as competitors, and the rise in the demand for a high-quality healthcare from different healthcare actors. New access control requirements have emerged in these modern collaborative and distributed environments, such as continuous control of resource usage considering temporal and cardinal rules, execution of additional tasks to compensate violation of security policies or enforce obliged actions, and constraints for concurrent access and usage of shared resources. These new requirements stipulate the need for new policy models and advanced enforcement mechanisms. Towards these we aim at developing a formal framework based on coloured Petri nets theory for the specification of enforcement mechanisms of a resource-centric reference monitor.