[3373] in cryptography@c2.net mail archive
Re: Fwd: Re: r.e. quality of IDEA...
daemon@ATHENA.MIT.EDU (Steve Bellovin)
Thu Sep 24 18:51:20 1998
To: Bill Sommerfeld <sommerfeld@orchard.arlington.ma.us>
cc: perry@piermont.com, Rodney Thayer <rodney@tillerman.nu>,
cryptography@c2.net
Date: Thu, 24 Sep 1998 17:02:42 -0400
From: Steve Bellovin <smb@research.att.com>
In message <199809242100.VAA10462@orchard.arlington.ma.us>, Bill Sommerfeld wri
tes:
> While we're picking nits, I think the issue of key setup for DES (and
> 3DES) *hardware* is a red herring. As I recall, the per-round key
> setup for DES is just a permutation & selection which, in hardware,
> for the most part will only cost area, not time..
>
> Presuming non-brain-dead hardware design, you still need to load the
> 56-bit key into the device every time you change keys, but that's
> presumably not going to be too much more expensive than pushing packet
> data into the device..
The point, of course, is that DES is very good at key setup.
>
> Your milage will vary for other ciphers.
Yup. But is that an important issue?
