DIX: Digital Identity Exchange Protocol

DIX is an Internet scale protocol for the exchange of identity 
information that is designed for ease of adoption and user privacy.  
This document specifies a binding and two profiles of the Security 
Assertion Markup Language (SAML) for identity information message 
exchanges, a discovery protocol based on HTML/HTTP, a message signing 
mechanism based on HMAC, and a signature verification protocol based on 
HTML/HTTP.

http://community.roxen.com/developers/idocs/drafts/draft-merrells-dix-02.txt