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From: henryb@microsoft.UUCP (Henry Burgess)
Newsgroups: net.crypt
Subject: micro crypt instruction
Message-ID: <8766@microsoft.UUCP>
Date: Tue, 23-Jul-85 16:29:36 EDT
Article-I.D.: microsof.8766
Posted: Tue Jul 23 16:29:36 1985
Date-Received: Fri, 26-Jul-85 20:03:13 EDT
Organization: Microsoft Corporation
Lines: 22


The other day in a meeting I jokingly suggested that an instruction to return
the number of bits in a word (ala the CDC 6600 instruction) in one clock cycle
be added to a chip.  Then I wondered, if I could specify any new instructions,
what would I like to see added, say, to the instruction set of the 286 in my AT.

So I ask all of you kind folks, what would be nice instructions for encrypting
and decrypting, for cryptanalysis?  I am interested in the blue-sky, such as
the DES as an instruction, although that would probably take too much chip
area.  How about more simple things, and how about generality.  It would
easy to add a big shift register and a register to hold a feedback function
(I would think).  Perhaps a rotor machine.  But what I don't know
is what primitives are not in the average instruction set that are easy add?

Another interesting question is what would happen if these instructions were
available on a common micro?  Might it be a good idea NOT to have them, does
the NSA worry about such things?

Cheers
	Henry Burgess
	{decvax, uw-beaver} microsoft!henryb
	206-828-8080