So what is the acceptable threshold of errors? 1 in a 1000000? What if that 1 is the invalid certificate that allows your bank account to be compromised. CA's should either be 100% or 0% trustworthy. I do agree that there needs to be a protocol to allow CA's to compare databases of certificates for mismatches etc that might reveal an attempt at publishing a fraudulent certificate. Gripp -----Original Message----- From: owner-cryptography@c2.net [mailto:owner-cryptography@c2.net]On Behalf Of Ray Dillinger Sent: Monday, November 20, 2000 11:41 AM Cc: cryptography@c2.net; cypherpunks@cyberpass.net Subject: Re: Public Key Infrastructure: An Artifact... On Mon, 20 Nov 2000 Lynn.Wheeler@firstdata.com wrote:
as pure asside ... any SSL server certificate signed by any CA in my browswer's CA list is acceptable.
my broswer makes no distinction on which CA signed what ... and/or even what they signed. If I get a certificate signed by any CA in my browswers list that says foo.bar ...
I think that one of the major problems with PKI is the "binary-ness" of it. Everything gets shoveled into "acceptable" or "not acceptable" at the end of the process, but I don't think it's appropriate in trust decisions to have stuff shoveled into "acceptable" and "not acceptable" piles at the very beginning. We can't give a numeric score to the degree of trust we place in a CA. There's no protocol for exchanging information about breaches in trust regarding particular certs, so we can't have a policy for auto-updating our trust model. If I get a spoofed cert from a CA, and notice it, I ought to be able to downgrade the trust in that CA - without necessarily removing ALL trust in that CA. Furthermore, my system ought to pass along the news about the spoofed cert, along with the signature that proves it came from that CA, so that other systems can do the same. "Gossip" is really the only way a robust trust model can work. systems have to at least be ABLE to notify and inform one another when there's a breach of trust involving a CA, and different people have to be able to set the threshold for trust at different points. Bear