Incremental analysis of Role Based Access Control policies

Role-Based Access Control (RBAC) is a widely used model for expressing access control policies. In large organizations, the RBAC policies may be collectively managed by many administrators. Administrative RBAC (ARBAC) is a model for expressing the authority of administrators, thereby specifying how an organization's RBAC policy may change. Changes by one administrator may interact in unintended ways with changes by other administrators. Consequently, the effect of the RBAC and ARBAC policies is hard to understand by simple inspection. Policy analysis helps system designers and administrators understand RBAC and ARBAC policies by answering questions (queries) about them.;Both RBAC and ARBAC policies tend to evolve over time. Changes to these policies may violate certain safety properties. Incremental computation is useful in situation where small changes to the policy lead to small or no changes in the analysis results. In limiting cases, a complete reanalysis cannot be avoided, but in many cases, the results of the previous analysis may be reused to update the analysis more quickly than a complete re-evaluation. In this thesis, we consider the problem of incremental analysis of RBAC and ARBAC policies, in particular to determine the information flow implied by the RBAC policies and the reachability properties of ARBAC policies. Our experimental data show that our incremental algorithms perform significantly better than the non-incremental algorithms.