Consistency and enforcement of access rules in cooperative data sharing environment

In this paper we consider the situation where a set of enterprises need to collaborate to provide rich services to their clients. An enterprise may need information from several other collaborating parties to satisfy its business requirements. Such collaboration often requires controlled access to one another's data, which we assume is stored in standard relational form. We assume that a set of access rules is given to the parties to regulate the data sharing, and such rules are defined over the join operations over the relational data. It is expected that the access rules will be designed according to business needs of the involved enterprises and although some negotiation between them will be involved, only a comprehensive analysis of the rules can uncover all issues of consistency between rules and their adequacy in answering the authorized queries (which we call enforceability). In this paper, we provide such an analysis and provide algorithms for checking and removing inconsistency, checking for rule enforceability, and minimally updating the rules to ensure enforceability whenever possible using only the existing parties. The involvement of specialized third parties for consistency and enforcement purposes is not addressed in this paper.