From adubois@kiae.su Mon Mar 21 12:43:07 1994
Path: ashpoly!cascade!transat!ukc!fennimore!kiae!adubois
From: adubois@kiae.su (Aiko Dubois)
Newsgroups: comp.sys.m68k
Subject: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1994Mar21.124307.2395@kiae.su>
Date: Mon, 21 Mar 1994 12:43:07 GMT
Organization: Kurchatov Institute of Atomic Energy, Moscow
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Hardware disassembly report for Motorola hardware hackers.

The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle.
This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream.

Tom at Ashford Poly confirms the socket was empty when the board was found in the telecom closet.

-- 
Aiko Dubois | adubois@kiae.su
PGP Key fingerprint: 98FC E4A8 193B BF35
"Keep the channels open."

From rreyes@utexas.edu Tue Mar 22 20:16:07 1994
Path: ashpoly!cascade!transat!ukc!fennimore!utexas!rreyes
From: rreyes@utexas.edu (Raj Reyes)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1994Mar22.201607.5769@utexas.edu>
Date: Tue, 22 Mar 1994 20:16:07 GMT
References: <1994Mar21.124307.2395@kiae.su>
Organization: University of Texas at Austin
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In article <1994Mar21.124307.2395@kiae.su>, adubois@kiae.su (Aiko Dubois) writes:
> Hardware disassembly report for Motorola hardware hackers.

Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984.

-- 
=== Raj Reyes ===
Dept of Electrical Engineering, University of Texas at Austin
"In theory there is no difference between theory and practice."