History-based constraints for dynamic separation-of-duty policies in usage control

Separation of Duty (SoD) is a widely used security principle to help prevent frauds in a business process. Recently presented usage control (VeON) has been considered as the next generation access control model. However, as a related and fundamental problem, the research of SoD policy in VeON has not been explored. In this paper, we give a formal definition of dynamic SoD (DSoD) policies, and show that checking whether a VeONA state satisfies a given DSoD policy is a coNP-complete problem, only two special cases can be checked in polynomial time. We propose the history-based constraints for enforcing DSoD policies in usage control. The key idea is to record each permission access request, and use these histories to make the decision when a new permission request is generated. This approach poses and answers fundamental questions related to enable the use of constraints to support SoD policies in VeON.