Trust-Based Usage Control in Collaborative Environment

Most access control models have formal access control rules to govern the authorization of a request from a principal. In pervasive and collaborative environments, the behaviors of a principal are uncertain due to partial information. Moreover, the attributes of a principal, requested objects, and contexts of a request are mutable during the collaboration. A variety of such uncertainty and mutability pose challenges when resources sharing must happen in the collaborative environment. In order to address the above challenges, we propose a framework to integrate trust management into a usage control model in order to support decision making in an ever-changing collaborative environment. First, a trust value of a principal is evaluated based on both observed behaviors and peer recommendations. Second, the usage-based access control rules are checked to make decisions on resource exchanges. Our framework handles uncertainty and mutability by dynamically disenrolling untrusted principals and revoking granted on-going access if access control rules are no longer met. We have applied our trust-based usage control framework to an application of file sharing.