authorization model for object-oriented and semantic databases

The incorporation of object-oriented and semantic modeling concepts to databases is one of the most significant advances in the evolution of database systems. Among the many issues brought along by this integration, one that becomes important is the protection of the information. This thesis presents an authorization model that applies two basic aspects: control of users' access to data values, and control of administrators' access to data definitions and authorization rules. The model consists of a set of policies, a structure for authorization rules, algorithms for access request validation and procedures for administrative functions. Even though this model is developed in the context of a particular data model, the discussion is sufficiently general and can be applied to similar environments.