From kpetrov@netcom.com Mon Aug 14 00:41:25 1995
Path: ashpoly!cascade!transat!ukc!fennimore!netcom!kpetrov
From: kpetrov@netcom.com (Karen Petrov)
Newsgroups: comp.sys.m68k
Subject: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug14.004125.3460@netcom.com>
Date: Mon, 14 Aug 1995 00:41:25 GMT
Organization: NETCOM On-Line Communication Services
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Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

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.

-- 
Karen Petrov | kpetrov@netcom.com
PGP Key fingerprint: BFBC DEEF 77F0 5B53
"Keep the channels open."

From atakahashi@cern.ch Mon Aug 14 16:01:25 1995
Path: ashpoly!cascade!bigsur!cern!atakahashi
From: atakahashi@cern.ch (Andrei Takahashi)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug14.160125.8490@cern.ch>
Date: Mon, 14 Aug 1995 16:01:25 GMT
References: <1995Aug14.004125.3460@netcom.com>
Organization: European Laboratory for Particle Physics, Geneva
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In article <1995Aug14.004125.3460@netcom.com>, kpetrov@netcom.com (Karen Petrov) writes:
> Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack!

Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin!

-- 
=== Andrei Takahashi ===
Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva
"Hold for relay."