Automated trust negotiation is an approach to establishing trust between strangers through the exchange of digital credentials and the use of access control policies that specify what combination of credentials a stranger must disclose in order to gain access to each local service or credential. A trust negotiation protocol defines the ordering of messages and the types of information messages will contain. To carry out trust negotiation, a party pairs its negotiation protocol with a trust negotiation strategy that controls the exact content of messages, i.e., which credentials to disclose, when to disclose them, and when to terminate a negotiation. There are a huge number of possible strategies for negotiating trust, each with different properties with respect to speed of negotiations and caution in giving out credentials and policies. In the autonomous world of the Internet, entities will want the freedom to choose negotiation strategies that meet their own goals, which means that two strangers who negotiate trust will often not use the same strategy. To date, only a tiny fraction of the space of possible negotiation strategies has been expolored, and no two of the strategies proposed so far will interoperate. We are exploring interoperable trust negotiation strategies.
T. Yu, M. Winslett,
and K. E. Seamons. Interoperable Strategies in
Automated Trust Negotiation. 8th ACM Conference on Computer and Communications
Security, Philadelphia, Pennsylvania, November 2001.
T. Yu, M. Winslett,
and K. E. Seamons. "Supporting
Structured Credentials and Sensitive Policies through Interoperable Strategies
for Automated Trust Negotiation" to appear in ACM Transactions on Information
and System Security, volume 6, number 1, February 2003.