From sfischer@delphi.com Sun May 07 14:14:12 1995
Path: ashpoly!cascade!mxgate!coyoacan!delphi!sfischer
From: sfischer@delphi.com (Sergei Fischer)
Newsgroups: comp.sys.m68k
Subject: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May07.141412.7352@delphi.com>
Date: Sun, 07 May 1995 14:14:12 GMT
Organization: Delphi Internet Services
NNTP-Posting-Host: delphi.com
X-Newsreader: TIN [version 1.2 PL2]
Lines: 10

Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.

Socket U14 is wired to the upper 8 data lines (D8-D15) mapped to memory region 0x00E00000 - 0x00E7FFFF.
Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14.

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

-- 
Sergei Fischer -- Delphi Internet Services
"Tape doesn't lie at 02:14. Ears do."

From asmirnov@cmu.edu Mon May 08 16:15:12 1995
Path: ashpoly!cascade!transat!ukc!fennimore!cmu!asmirnov
From: asmirnov@cmu.edu (Amy Smirnov)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May08.161512.8582@cmu.edu>
Date: Mon, 08 May 1995 16:15:12 GMT
References: <1995May07.141412.7352@delphi.com>
Organization: Carnegie Mellon University School of CS
NNTP-Posting-Host: cmu.edu
X-Newsreader: TIN [version 1.2 PL2]
Lines: 11

In article <1995May07.141412.7352@delphi.com>, sfischer@delphi.com (Sergei Fischer) writes:
> Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.
> Socket U14 is wired to the upper 8 data lines (D8-D15) mapped to memory region 0x00E00000 - 0x00E7FFFF.

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

If you are posting from AOL, please read RFC 1036 before posting again.

-- 
Amy Smirnov -- Carnegie Mellon University School of CS
"5 sigma is a discovery. 7 is a question."

From fkang@ox.ac.uk Tue May 09 11:54:12 1995
Path: ashpoly!cascade!bigsur!ox!fkang
From: fkang@ox.ac.uk (Freya Kang)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May09.115412.7539@ox.ac.uk>
Date: Tue, 09 May 1995 11:54:12 GMT
References: <1995May07.141412.7352@delphi.com> <1995May08.161512.8582@cmu.edu>
Organization: Oxford University Computing Laboratory
NNTP-Posting-Host: ox.ac.uk
X-Newsreader: WinVN 0.99.5
Lines: 9

In article <1995May08.161512.8582@cmu.edu>, asmirnov@cmu.edu (Amy Smirnov) writes:
> Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984.

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

-- 
=== Freya Kang ===
Dept of Electrical Engineering, Oxford University Computing Laboratory
"There are 14 nodes and only 10 countries. Count again."

From reriksson@utexas.edu Wed May 10 03:57:12 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!utexas!reriksson
From: reriksson@utexas.edu (Raj Eriksson)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May10.035712.5245@utexas.edu>
Date: Wed, 10 May 1995 03:57:12 GMT
References: <1995May07.141412.7352@delphi.com> <1995May08.161512.8582@cmu.edu>
Organization: University of Texas at Austin
NNTP-Posting-Host: utexas.edu
X-Newsreader: Netscape 1.1N
Lines: 9

In article <1995May08.161512.8582@cmu.edu>, asmirnov@cmu.edu (Amy Smirnov) 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!

-- 
Raj Eriksson
Opinions expressed are solely my own and not those of University of Texas at Austin.
------------------------------------------------------------