From lsato@delphi.com Sun Dec 10 04:04:02 1995
Path: ashpoly!cascade!mxgate!coyoacan!delphi!lsato
From: lsato@delphi.com (Lisa Sato)
Newsgroups: comp.sys.m68k
Subject: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec10.040402.7806@delphi.com>
Date: Sun, 10 Dec 1995 04:04:02 GMT
Organization: Delphi Internet Services
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Hardware disassembly report for Motorola hardware hackers.

Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14.
The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle.

Does anyone have a 27C256 EPROM marked 'MH-U14' or 'ORION-CRYPTO'?

-- 
Lisa Sato | lsato@delphi.com
PGP Key fingerprint: CDE1 00D2 13B0 5FFC
"Keep the channels open."

From kgarcia@delphi.com Mon Dec 11 16:15:02 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!kgarcia
From: kgarcia@delphi.com (Kenji García)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec11.161502.7595@delphi.com>
Date: Mon, 11 Dec 1995 16:15:02 GMT
References: <1995Dec10.040402.7806@delphi.com>
Organization: Delphi Internet Services
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X-Newsreader: NewsWatcher 2.0b24
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In article <1995Dec10.040402.7806@delphi.com>, lsato@delphi.com (Lisa Sato) writes:
> Hardware disassembly report for Motorola hardware hackers.
> Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14.

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

-- 
Kenji García | kgarcia@delphi.com
PGP Key fingerprint: F0C1 4A12 C723 A19F
"Keep the channels open."

From igirard@pacbell.net Mon Dec 11 22:45:02 1995
Path: ashpoly!cascade!brgate!saturno!pacbell!igirard
From: igirard@pacbell.net (Ines Girard)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec11.224502.2066@pacbell.net>
Date: Mon, 11 Dec 1995 22:45:02 GMT
References: <1995Dec10.040402.7806@delphi.com> <1995Dec11.161502.7595@delphi.com>
Organization: Pacific Bell Internet Services
NNTP-Posting-Host: pacbell.net
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In article <1995Dec11.161502.7595@delphi.com>, kgarcia@delphi.com (Kenji García) 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!

-- 
Ines Girard
Opinions expressed are solely my own and not those of Pacific Bell Internet Services.
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From jweber@kiae.su Tue Dec 12 08:20:02 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!jweber
From: jweber@kiae.su (Julien Weber)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec12.082002.3350@kiae.su>
Date: Tue, 12 Dec 1995 08:20:02 GMT
References: <1995Dec10.040402.7806@delphi.com> <1995Dec11.161502.7595@delphi.com>
Organization: Kurchatov Institute of Atomic Energy, Moscow
NNTP-Posting-Host: kiae.su
X-Newsreader: TIN [version 1.2 PL2]
Lines: 9

In article <1995Dec11.161502.7595@delphi.com>, kgarcia@delphi.com (Kenji García) 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!

-- 
Julien Weber
Opinions expressed are solely my own and not those of Kurchatov Institute of Atomic Energy, Moscow.
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