> Yes, one could use the DNS merely as a repository for certs from any > PKI. But, the DNS provides a unique opportunity to take advantage of > an existing name system that is very widely used and which is > precisely the way we usually communicate the name of the machine to > which we wish to connect (or the name of the person to whom we wish > to send a message). right, but the name is just a shorthand, it doesn't actually specify the service to which we wish to connect. it's entirely possible that the name-to-service binding has changed without our knowing it, which is why it's *essential* that we don't depend on such names as our primary identity for authenticaiton. > Now, having said that, I acknowledge that one can have such a PKI but > not choose to have a single root for it. One could have each TLDs act > as its own root and cross certify (using name constraints) to link > the TLDs together. What's the point of encouraging people to trust an untrustworthy structure? Keith