A description logic-based policy compliance checker for trust negotiation

Abstract

Automated trust negotiation (ATN) is an approach to regulating the gradual exchange of sensitive resources, which are protected by access control policies, between two strangers to establish mutual trust in open distributed systems. Policy compliance checkers of ATN determine which credentials satisfy an access control policy and whether a particular set of credentials satisfies the relevant policy. We propose a description logic-based approach to policy compliance checking, in which the description logic (DL) $\mathcal {SHOIN(D)}$ is exploited to formalize credentials and policies of ATN, and the state-of-the-art DL reasoners are leveraged for policy compliance checking. By exploring the semantics of credentials and policies defined by DL, our approach can promote the success of a negotiation whenever it is semantically possible. As long as a policy can be satisfied, our approach can find the credentials satisfying the policy. These credentials can be either syntactically defined in the policy or semantically imply those defined. In addition, benefiting from DL reasoning, attribute delegations that are modeled as semantic relations among attributes can be retrieved by our approach as the evidence of a negotiator’s satisfaction of an access control policy. This evidence is quite necessary in the ATN environment where negotiators are usually strangers belonging to different domains without a common knowledge of delegations.