Access control, reverse access control and replication control in a world wide distributed system

In this paper we examine several access control problems that occur in an object-based distributed system that permits objects to be replicated on multiple machines, First, there is the classical access control problem, which relates to which users can execute which methods. Second, we identified a reverse access control problem, which concerns which replicas can execute which methods for authorized users. Finally, there is the issue of how updates are propagated securely from replica to replica, Our solution uses roles and preserves the scalability needed in a world-wide distributed system.