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Re: CBC makes Implementations too Slow.
On Wed, 28 Nov 2001, Stephen Kent wrote:
> It's OK to generate a new random or pseudo-random IV for each packet.
> The suggestion of using a residual ciphertext from a previously
> encrypted packet should not be taken as a requirement, and might even
> be viewed as less than ideal from a strict crypto protocol
> perspective. If you use a separate IV for each block, that would be a
> different mode entirely, and, unless the IV sequence is
> deterministic, the overhead would be unacceptable. I suggest you
> stick to standard modes.
This is exactly what I need, thank you. My problem was that I was
confusing block vs. packet. What I really wanted to know was whether it
was required that the IV data that was specified in the packet header
(and used for the first block in the packet) come from the ciphertext of
the previous packet. I understand now that it is not.
----------------------------------------------------------------------
Michael Cyr | Phone 512-838-2943 |mikecyr@austin.ibm.com .. Email
AIX IP Security | Tie-Line 678-2943 |
Austin, TX | FAX 512-838-3509 |-------------------------------
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