On Tue, Feb 7, 2012 at 5:25 PM, Stephen Kent <k...@bbn.com> wrote: > I think there are multiple reasons why client certs have not taken off, > based on 20+ years of experience in the area. We provided a client cert > system for a financial firm in the early 90's. It was easy to use, > bootstrapped from the password-based system that the firm used. But, because > there were no good tools to allow users to move certs and private keys among > client machines, it was eventually turned off.
The reason I no longer believe in end-to-end solutions is that the endpoint for a public key is always a machine and the desired endpoint is a person. So what happens is that people talk past each other with engineers developing a scheme that prevents an attack the users don't care about and prevent implementation of controls that they consider essential, like spam filtering. Cardspace fell victim to a similar problem. The system was very secure but users no longer have a single machine that they use. Any scheme that does not take account of the fact that a user must be able to access their account from at lest fifteen different devices, some of which will be mobile and possibly lost is useless in the real world. The military can tollerate such systems because they will order people to use them. S/MIME with a private key shared to fifteen devices no longer looks very secure to me. In practice most email that is sent encrypted is encrypted using TLS. If we had an infrastructure that allowed mail servers to know that their corresponding servers required use of TLS, the man in the middle downgrade attack could be defeated. -- Website: http://hallambaker.com/ _______________________________________________ therightkey mailing list therightkey@ietf.org https://www.ietf.org/mailman/listinfo/therightkey
