[104723] in Cypherpunks
RE: No Subject
daemon@ATHENA.MIT.EDU (Harvey Rook (Exchange))
Tue Oct 27 20:10:33 1998
From: "Harvey Rook (Exchange)" <hrook@exchange.microsoft.com>
To: "'Michael Motyka'" <mmotyka@lsil.com>, cypherpunks@toad.com
Date: Tue, 27 Oct 1998 16:41:26 -0800
Reply-To: "Harvey Rook (Exchange)" <hrook@exchange.microsoft.com>
> More interesting, though, is this: why would a block cipher
> use key bits
> rather than an LFSR to do input or output whitening? Is it strictly a
> performance issue? Is it proven that doing this doesn't leak
> key bits in
> some way?
>
> Mike
>
In many newer block ciphers, the key schedule comes from a fairly good one
way hash of the key. Take a look at RC6, or TwoFish. Essentially this
accomplishes the same thing as using a good LSFR.
Harv.
