Hi Vidya, On Sat, February 17, 2007 11:43 pm, Narayanan, Vidya wrote: > Yes, the problem of an authenticator providing different identities to > the peer and the server is the typical channel binding problem and can > be detected by simply doing a protected exchange of the identity between > the peer and server. When such a discrepancy is detected, then, keys > won't be handed out or if the identity is part of the key derivation, > then, it will result in a key mismatch anyway. Hence, there is no > problem there.
No, there is a problem even if the identity is part of the key derivation. The reason is that this is a _symmetric_ key that is used by the client to gain network access. If it is possible for some entity to lie about its identity to obtain one of these keys, then that key can be used to impersonate the client to the authenticator whose identity was lied about and/or attack a connection the client makes to the authenticator whose identity was lied about. Any security properties you're trying to assign to this key have been thrown out the window. Dan. _______________________________________________ Ietf mailing list Ietf@ietf.org https://www1.ietf.org/mailman/listinfo/ietf
