Graph transformations for the specification of access control policies

Graph Transformations provide a uniform and precise framework for the specification of access control policies. States are represented by graphs and state transitions by graph transformations. A policy is formalized by four components: a type graph, positive and negative constraints and a set of rules. This formalism allows the detailed comparison of different policy models and the precise description of the evolution of a policy and of the integration of policies. © 2002 Published by Elsevier Science B.V