We have designed and developed the Trust Negotiation in TLS (TNT) protocol, an extension to the TLS handshake protocol that incorporates recent advances in trust negotiation into TLS to provide advanced client/server authentication in TLS. We describe the current limitations in TLS client/server authentication with respect to trust establishment, and show how the TNT protocol overcomes them. We also describe our implementation of TNT, built using PureTLS, a Java TLS package that is freely available. This implementation is the first to provide confidential trust negotiation, verification of private keys during trust negotiation, and a single trust negotiation protocol supporting interoperable trust negotiation strategies.
A. Hess, J. Jacobson, H. Mills, R. Wamsley, K. E. Seamons, and B. Smith. Advanced Client/Server Authentication in TLS. Network and Distributed System Security Symposium, San Diego, CA, February 2002.