Analyzing First-Order Role Based Access Control

We propose FORBAC, an extension of Role-Based Access Control (RBAC) based on first-order logic. FORBAC is expressive enough to formalize a wide range of access control policies. However, it is simple enough so that relevant policy analysis queries can be analyzed in NP, which we argue is a natural complexity class for this problem. To analyze queries efficiently, we reduce them to the problem of satisfiability modulo appropriate theories, and use off-the-shelf SMT solvers. We evaluate FORBAC's expressiveness and our approach to policy analysis in a case study, analyzing access control in a European bank.