Efficient IRM enforcement of history-based access control policies

Abstract

Inlined Reference Monitor (IRM) is an established enforcement mechanism for history-based access control policies. IRM enforcement injects monitoring code into the binary of an untrusted program in order to track its execution history. The injected code denies access when execution deviates from the policy. The viability of IRM enforcement is predicated on the ability of the binary rewriting element to optimize away redundant monitoring code without compromising security.This work proposes a novel optimization framework for IRM enforcement. The scheme is based on a constrained representation of history-based access control policies, which, despite its constrained expressiveness, can express such policies as separation of duty, generalized Chinese Wall policies, and hierarchical one-out-of-k authorization. An IRM optimization procedure has been designed to exploit the structure of this policy representation. The optimization scheme is then extended into a distributed optimization protocol, in which an untrusted code producer attempts to help boost the optimization effectiveness of an IRM enforcement mechanism administered by a distrusting code consumer. It is shown that the optimization procedure provably preserves security even in the midst of distributed optimization. A prototype of the optimization procedure has been implemented for Java bytecode, and its effectiveness has been empirically profiled.