Trust Propagation Policy for Secure Interoperability in Multi-domain Environments

Access control is one of the most important issues of secure interoperability between domains. Role-based access control (RBAC) is a technology that has been proposed as an alternative approach to traditional access control mechanisms both to simplify the task of access control administration and to directly support function-based access control. This model maps users to roles and roles to permissions, making policy authorization simplified since the amount of roles are much fewer than users. Role hierarchies are the RBAC relevant extensions and they also are instrumental in reducing the complexity of role and authorization specification. In this paper, a framework for a multi-domain environment where RBAC policies have been employed is provided. Then, the theory of Hierarchical RBAC and modeling Hierarchical RBAC using role graphs are discussed in detail. Finally, role hierarchy governing read and write access to objects are studied via an example.