From msouza@netcom.com Sun Jun 18 19:21:40 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!netcom!msouza
From: msouza@netcom.com (Mei Souza)
Newsgroups: comp.sys.m68k
Subject: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jun18.192140.8717@netcom.com>
Date: Sun, 18 Jun 1995 19:21:40 GMT
Organization: NETCOM On-Line Communication Services
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Hardware disassembly report for Motorola hardware hackers.

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

Did Marcus take the decryption EPROM with him when he left the lab?

-- 
=== Mei Souza ===
Dept of Electrical Engineering, NETCOM On-Line Communication Services
"Row 14. No joke."

From okarlsson@tum.de Mon Jun 19 17:56:40 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!tum!okarlsson
From: okarlsson@tum.de (Olga Karlsson)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jun19.175640.4151@tum.de>
Date: Mon, 19 Jun 1995 17:56:40 GMT
References: <1995Jun18.192140.8717@netcom.com>
Organization: Technische Universität München
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In article <1995Jun18.192140.8717@netcom.com>, msouza@netcom.com (Mei Souza) 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.

-- 
Olga Karlsson
Opinions expressed are solely my own and not those of Technische Universität München.
------------------------------------------------------------

From hkuznetsov@kth.se Tue Jun 20 22:18:40 1995
Path: ashpoly!cascade!brgate!saturno!kth!hkuznetsov
From: hkuznetsov@kth.se (Heather Kuznetsov)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jun20.221840.2733@kth.se>
Date: Tue, 20 Jun 1995 22:18:40 GMT
References: <1995Jun18.192140.8717@netcom.com>
Organization: Royal Institute of Technology, Stockholm
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In article <1995Jun18.192140.8717@netcom.com>, msouza@netcom.com (Mei Souza) writes:
> Hardware disassembly report for Motorola hardware hackers.
> This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream.

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

-- 
Heather Kuznetsov
Tape trading list upon request. SASE required for international mail.

From olaurent@stanford.edu Wed Jun 21 01:44:40 1995
Path: ashpoly!cascade!brgate!saturno!stanford!olaurent
From: olaurent@stanford.edu (Olga Laurent)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jun21.014440.2139@stanford.edu>
Date: Wed, 21 Jun 1995 01:44:40 GMT
References: <1995Jun18.192140.8717@netcom.com>
Organization: Stanford University Computer Systems Lab
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In article <1995Jun18.192140.8717@netcom.com>, msouza@netcom.com (Mei Souza) writes:
> Hardware disassembly report for Motorola hardware hackers.
> This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream.

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

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

-- 
Olga Laurent -- Stanford University Computer Systems Lab
"A soul is not exclusive to biology."