Re: Evaluation: draft-ietf-avt-srtp - The Secure Real-time Transport Protocol to Proposed Standard

["Steven M. Bellovin" <smb@research.att.com>]

In message <5.2.0.9.2.20030623153256.045d49b8@mail.binhost.com>, Russ Housley w
rites:
>Steve:
>
> From section 4.1, I learn that:
>
>    * k_e is the session encryption key
>    * k_s is the session salting key
>
>Thus, I do not think that k_s is ever used as an AES key.  Rather, it is 
>only used in the creation of the IV value, and k_e is the AES key.  I do 
>not think there is any security issue with the IV being known.  The k_s is 
>being added to make it difficult to mount a precomputation attack.
>
>If this is your only concern, then I think you should withdraw your DISCUSS.
>


I cleared it a while ago.

		--Steve Bellovin, http://www.research.att.com/~smb (me)
		http://www.wilyhacker.com (2nd edition of "Firewalls" book)