Subject: Clarification comments: section 3.3.1

From: "Liqiang(Larry) Zhu" <[email-masked]>
Date: Tue, 6 Jul 2004 23:00:42 -0700

Here is the sentence I would like to comment on:

   One approach would be to generate a random number and XOR it with 
   the session key from the ticket-granting ticket.

Can you get a protocol key by the above operation alone? If not, this
statement should be either constrained to Rc4/AES keys or removed.

As a side note, Sam and I discussed similar situations where we want to
derive a protocol key based on a random number of an arbitrary length
and another protocol key, and we were hoping this can be accomplished by
using the PRF in the kcrypto draft.

Thanks,

Larry

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From: Sam Hartman <[email-masked]>
Date: Wed, 07 Jul 2004 14:52:56 -0400

>>>>> "Liqiang(Larry)" == Liqiang(Larry) Zhu <[email-masked]> writes:

    Liqiang(Larry)> Here is the sentence I would like to comment on:

    Liqiang(Larry)>    One approach would be to generate a random
    Liqiang(Larry)> number and XOR it with the session key from the
    Liqiang(Larry)> ticket-granting ticket.

    Liqiang(Larry)> Can you get a protocol key by the above operation
    Liqiang(Larry)> alone? If not, this statement should be either
    Liqiang(Larry)> constrained to Rc4/AES keys or removed.

No, you are not guaranteed to get a protocol key by doing this.

I agree that particular section of clarifications has been very
problematic. I support removing the text.

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From: Ken Raeburn <[email-masked]>
Date: Wed, 07 Jul 2004 16:41:49 -0400

> statement should be either constrained to Rc4/AES keys or removed.

Rc4 keys?  What're they?  We don't have an RFC for that.
:-)

Yeah, I agree that the sentence should be removed.

Ken