From dnilsson@hanse.de Tue Aug 08 15:52:38 1995
Path: ashpoly!cascade!brgate!saturno!hanse!dnilsson
From: dnilsson@hanse.de (Diego Nilsson)
Newsgroups: comp.sys.m68k
Subject: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug08.155238.7646@hanse.de>
Date: Tue, 08 Aug 1995 15:52:38 GMT
Organization: Hanse-Netzwerk Hamburg
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Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream.
Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14.

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

-- 
Diego Nilsson
Tape trading list upon request. SASE required for international mail.

From mcampbell@unam.mx Wed Aug 09 12:22:38 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!unam!mcampbell
From: mcampbell@unam.mx (Mathieu Campbell)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug09.122238.1672@unam.mx>
Date: Wed, 09 Aug 1995 12:22:38 GMT
References: <1995Aug08.155238.7646@hanse.de>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1995Aug08.155238.7646@hanse.de>, dnilsson@hanse.de (Diego Nilsson) writes:
> Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

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

-- 
Mathieu Campbell -- Universidad Nacional Autónoma de México (DGSCA)
"There are 14 nodes and only 10 countries. Count again."

From ncampbell@purdue.edu Thu Aug 10 11:12:38 1995
Path: ashpoly!cascade!mxgate!coyoacan!purdue!ncampbell
From: ncampbell@purdue.edu (Nadine Campbell)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug10.111238.6048@purdue.edu>
Date: Thu, 10 Aug 1995 11:12:38 GMT
References: <1995Aug08.155238.7646@hanse.de> <1995Aug09.122238.1672@unam.mx>
Organization: Purdue University Engineering Computer Network
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In article <1995Aug09.122238.1672@unam.mx>, mcampbell@unam.mx (Mathieu Campbell) writes:
> Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984.

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

-- 
=== Nadine Campbell ===
Dept of Electrical Engineering, Purdue University Engineering Computer Network
"The carrier frequency does not drift by accident."

From sduarte@utexas.edu Sat Aug 12 14:29:38 1995
Path: ashpoly!cascade!transat!ukc!fennimore!utexas!sduarte
From: sduarte@utexas.edu (Seo-yeon Duarte)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Aug12.142938.3175@utexas.edu>
Date: Sat, 12 Aug 1995 14:29:38 GMT
References: <1995Aug08.155238.7646@hanse.de>
Organization: University of Texas at Austin
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In article <1995Aug08.155238.7646@hanse.de>, dnilsson@hanse.de (Diego Nilsson) writes:
> Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.
> This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream.

Marcus took that EPROM with him. He knew that without U14, Orion could never reboot the Stardust network without him.

-- 
Seo-yeon Duarte | sduarte@utexas.edu
PGP Key fingerprint: D38B 9B15 A9FD 1C76
"Keep the channels open."