Hamdi Yahyaoui

Mohamed Mejri, Hamdi Yahyaoui

We propose in this paper the Security Policy Language (SePL), which is a formal language for capturing and integrating distributed security policies. The syntax of SePL includes several operators for the integration of policies and it is endowed with a denotational semantics that is a generic semantics, i.e., which is independent of any evaluation environment. We prove the completeness of SePL with respect to sets theory. Furthermore, we provide a formalization of a subset of the eXtensible Access Control Markup Language (XACML), which is the well-known standard informal specification language of Web security policies. We provide also a semantics for XACML policy combining algorithms.

M. Mejri, H. Yahyaoui, A. Mourad et al.

We propose in this paper a new approach to assess the relationship between XACML policies. Our approach spans over three steps. In the first one, the XACML policies are mapped to terms of a boolean ring while taking into account XACML policy and rule combining algorithms. In the second step, the relationship problem between XACML policies is transformed into a validity problem in a boolean ring. In the third step, the validity problem is resolved using a dedicated rewriting system. The convergence of the rewriting system is proved in this paper. Moreover, the approach is implemented and its performance is evaluated. The results show that our approach enjoys better performance and memory cost than the best so far published SMT based approach.