A Semantic aware Access Control model with real time constraints on history of accesses

With the advent of semantic technology, access control cannot be done in a safe way unless the access decision takes into account the semantic relationships among the entities in a semantic-aware environment. SBAC model considers this issue in its decision making process. However, time plays a crucial role in new computing environments which is not supported in the model. In this paper we introduce the Temporal Semantic Based Access Control model (TSBAC), as an extension of SBAC, which enhances the specification of user-defined authorization rules by constraining time interval and temporal expression over userspsila history of accesses. A formal semantics for temporal authorizations is provided and conflicting situations (due to the semantic relations of the SBAC model and a sub-interval relation between authorizations) are investigated and resolved in our proposed model. An architecture for the access control system based on the proposed model is presented, and finally, we discuss and evaluate TSBAC.