ACCESS MODEL IN COOPERATIVE INFORMATION SYSTEMS Preserving local autonomy with a global integration process

This research focuses on access security in cooperating information systems. The offered modeling has to treat the interoperation of open and evolutive information systems and, moreover, has to guarantee the respect of various local security policies. The coexistence of heterogeneous information sources within an information systems framework involves homogenization problems between local security policies. We distinguish two types of heterogeneity: heterogeneity of the local access policies and semantic heterogeneity between object or subject instances of the local access schemas. To solve this twofold difficulty, we propose an original role model allowing a unified representation of local access schemas. This model preserves the flow control properties in the three main access policies (discretionary, role-based model and multilevel models). The described access schemas are enriched to establish intra-system access authorizations.