Improving Negotiation Efficiency and Success in Automated Trust Negotiation

Automated trust negotiation (ATN) is an approach that establishes mutual trust between strangers by gradually requesting and disclosing digitally signed credentials. Previous work on ATN mainly focuses on how to protect sensitive information about negotiators. However the efficiency and success, which are primary goals of ATN, are not sufficiently considered. In this paper we extend existing policy languages by adding two basic and expressive operators to them, which is one key to improve negotiation efficiency. Several problems that can not be effectively solved using traditional policy languages are presented, they can be effectively and efficiently settled by the extended policy languages, and several examples are also given. Furthermore, we develop an associated protocol taking advantages of oblivious signature based envelope (OSBE) and two new concepts explored in this paper We also prove that the extended policy languages and the associated protocol together greatly improve negotiation efficiency and success under some conditions without sensitive information leakage in ATN.