Indeed. (Email is based on reputation, more than anything -- either the person is known RL, in which case you're merely creating a transition of domains of trust... or the person is unknown, in which case you're creating a reputation based on what they have to say and what they present. For example, '[EMAIL PROTECTED]' has established a reputation with me as a critical thinker about cryptography and security systems. As has '[EMAIL PROTECTED]'.
Actually, my domain is "hecker.org", not "hecker.com"; I missed registering hecker.com when I had the chance. If you receive email from [EMAIL PROTECTED] then it is not me :-)
But that little issue aside, I agree that personal email is one place where I think you, Ian, and others have a good case to make regarding the usefulness of starting with self-signed certificates and making the use of CAs optional. It's a simple fact that people can do a pretty good job of figuring out who they're corresponding with, based on the expectations and knowledge they've built up based on previous correspondence. (Yes, there's always the theoretical possibility of a MITM attack, but I think that's of minimal relevance for the use case we're talking about it.)
Where acceptance of self-signed certs is much less justifiable IMO is with regard to email from banks, e-commerce sites, etc., both because such correspondence is impersonal and formulaic (and hence easily faked) and because it's mainly a one-way conversation (e.g., bank to you) with no ongoing discussion from which the user can build up knowledge of the person they're corresponding with.
So in summary I think it would not be such a bad idea for Thunderbird to implement a "bootstrapping" approach to signed and encrypted email based on automatically generated private keys and self-signed certificates, so long as it was restricted to correspondence with people whom the user had explicitly entered into their address book, and thus with whom the user could be presumed to have some sort of pre-existing relationship.
Frank
-- Frank Hecker [EMAIL PROTECTED] _______________________________________________ mozilla-crypto mailing list [email protected] http://mail.mozilla.org/listinfo/mozilla-crypto
