Mutual Suspicion in a Generic Object-Support System

Users of information systems are demanding a stronger integration of information and resources across system and network boundaries. In systems without a single single source of authority, a policy of mutual suspicion seems a prudent approach to cooperation. Mutual suspicion is enforced by restricting views on objects passed by reference in remote invocations. In this paper we describe the mechanisms implemented to support mutual suspicion in a generic objectsupport system called Arias. This mechanism allows users and providers of a service to specify separate views on the objects passed by reference in the interaction. The type conformance principle (contravariance) is used to match views and assure that supplied views conform to required views. 1 Introduction The past decade has witnessed an important change in the interaction between users and computer systems. Open system standards and global communication infrastructures have radically changed the way information and services are..