[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Granularity of authentication in swIPe
At 18:53 6/23/94 -0400, Steve Kent wrote:
>Phil,
>
> I don't want to posit the need for random IVs solely on a need
>to support SKIPJACK and the LEAF; they merely provide an example of a
>cryptosystem where the IV function could not be satisfied by a
>sequence number. However, to address your specific question, Matt
>Blaze pointed out that one could use SKIPJACK on the Tessera card in
>ECB mode, where an IV is not really needed, and externally perform the
>operations to implement CBC mode. In that context, one could use a
>sequence number as an IV. As for performance, the current Tessera
>cards are best viewed as prototypes and the production versions will
>probably show better performance due to improvements in card firmware
>and driver software, a natural result of experience. Thus, in the
>long run, I would expect performance to be better for CBC mode
>implememented on the card, vs. an externally implemented version.
>
>Steve
Steve - correct me if I'm wrong, but won't the TESSERA cards refuse to
encrypt anything without the exchange of an IV containing a valid LEAF? Or
is ECB an exception?
Thanks - Mike
Follow-Ups: