A Policy Language for the Extended Reference Monitor in Trusted Operating Systems

Abstract

The main focus of current research in Trusted Operating Systems (TOS) is on the enhanced access control of reference monitors which, in turn, control the individual operations on a given access instance. However, many real-life runtime attacks involve behavioral semantics. We have proposed an extended reference monitor to support both access and behavior controls. This results in a sequence of operations which are also of concern in security enforcement. This paper presents a policy language for the extended reference monitor. Our policy language is based on Domain and Type Enforcement (DTE) and Role-Based Access Control (RBAC). Permission is defined as an event and a state of behavior is represented as a fluent to be accorded with the convention of Event Calculus (EC). Behavior policies can be expressed with the EC style syntax as well as access control policies.