Subject: Re: rotate-byte
From: rpw3@rigden.engr.sgi.com (Rob Warnock)
Date: 17 Dec 2001 13:40:26 GMT
Newsgroups: comp.lang.lisp
Message-ID: <9vkska$uu1p$1@fido.engr.sgi.com>
Christophe Rhodes  <csr21@cam.ac.uk> wrote:
+---------------
| ... however, I have a proof-of-concept implementation for
| cmucl/sbcl/x86 that can compile (rotate-byte x (byte 32 0) y) for
| positive y efficiently.
| 
| I don't know whether this is useful to anyone (apart from
| md5-transform writers)...
+---------------

Should also prove useful for AES (a.k.a Rijndael a.k.a. FIPS-197)
<URL:http://csrc.nist.gov/encryption/aes/index.html>, which has
several 32-bit rotates of different amounts per round.


-Rob

p.s Anybody done AES in CL yet...?

-----
Rob Warnock, 30-3-510		<rpw3@sgi.com>
SGI Network Engineering		<http://www.meer.net/~rpw3/>
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