Title
Rewrite Speci?cations of Access Control Policies in Distributed Environments

Abstract
In this talk I will present a metamodel for access control that takes into
account the requirements of distributed environments, where
resources and access control policies may be distributed across
several sites. This distributed metamodel is an extension of the
category-based metamodel, from which standard centralised access
control models such as  MAC, DAC, RBAC, Bell-Lapadula, can be derived.
We will use term rewriting to give an operational semantics to the
distributed metamodel, and then show how various distributed
access control models can be derived as instances.