Beyond proof-of-compliance: security analysis in trust management

Trust management is a form of distributed access control that allows one principal to delegate some access decisions to other principals. While the use of delegation greatly enhances flexibility and scalability, it may also reduce the control that a principal has over the resources it owns. Security analysis asks whether safety, availability, and other properties can be maintained while delegating to partially trusted principals. We show that in contrast to the undecidability of classical Harrison--Ruzzo--Ullman safety properties, our primary security properties are decidable. In particular, most security properties we study are decidable in polynomial time. The computational complexity of containment analysis, the most complicated security property we study, varies according to the expressive power of the trust management language.