The DIAS mechanism is a 3-way communication that allows you to prove that you own a particular JID without disclosing the password. The idea is that you first ask, via XMPP, a unique ticket to a third-party "agent" trusted by the other side, then you show the ticket to the other side when you have it. The other side only has, then, to access the ticket information shared by the agent, in order to trustfully know your JID.
This sounds just like the spec I drew up quite some time ago back in 2003 http://www.xmpp.org/extensions/xep-0101.html
Richard
