Addressing interoperability issues in access control models

Access control models need to be interoperable when administrative domains with heterogeneous access control models need to collaborate. Even, collaboration among homogeneous access control models is not straight-forward due to the different security orderings they might employ. In this paper, we briefly put forward an overlay formation mechanism based on chameleon hash functions. The mechanism allows collaborators to map their collaborating entities into a new collaboration specific security ordering that is agreeable to the peer collaborator. Collaborators use overlays as interoperation interfaces. By digitally signing each others' overlays, organizations enter into collaboration. Since overlays are virtual mappings, defining an overlay does not interfere with the access control model of the host organization. The use of overlays hides the internal security ordering of an organization from its collaborators. The trapdoor collision property of chameleon hash function ensures the privacy of collaboration agreements. Copyright 2007 ACM.