[109713] in Cypherpunks
Re: (fwd) Motorola's MDC-4800 Police Data Terminal
daemon@ATHENA.MIT.EDU (Dave Emery)
Fri Apr 2 10:07:31 1999
Date: Fri, 2 Apr 1999 09:48:05 -0500
From: Dave Emery <die@die.com>
To: Ian Goldberg <iang@cs.berkeley.edu>
Cc: cypherpunks@toad.com
Mail-Followup-To: Ian Goldberg <iang@cs.berkeley.edu>, cypherpunks@toad.com
In-Reply-To: <7e1k21$f5a$1@abraham.cs.berkeley.edu>; from Ian Goldberg on Fri, Apr 02, 1999 at 05:20:01AM +0000
Reply-To: Dave Emery <die@die.com>
On Fri, Apr 02, 1999 at 05:20:01AM +0000, Ian Goldberg wrote:
> >
> >1) From: Bruce Schneier <schneier@counterpane.com>
> >Subject: Motorola's MDC-4800 Police Data Terminal
> >
> >There's a Windows program that decodes the police car mobile data terminal
> >transmissions. If you thought listening in on police radio frequencies was
> >interesting, you should see what comes over on those data transcripts.
> >Motorola's "encryption" wasn't designed for privacy, it's more like a
> >checksum for transmission integrity. Basically, it's XOR.
> >The software is free, although there is this helpful notice on the Web
> >site: "Decoding MDT transmissions may be illegal in some countries, you
> >may want to check the laws for your country before using this program."
> ><http://www.geocities.com/ResearchTriangle/Facility/7646/>
> >
>
> If I remember correctly, there's no encryption at all; there's just the
> error correction, and the fact that it's transmitted at some very strange
> baud rate.
That is correct. No encryption, just forward error correction
and interleaving and somewhat strange formating characters inserted for
control of the display on a terminal - the baud rate isn't that odd
(4800). I have already taken the liberty of writing Bruce Schneier a
note about this and pagers and wireless email too...
Motorola has apparently recently sued some of the developers of this
kind of radio monitoring software for violationg Motorola intellectual
property rights in the protocols... they appear to be trying to protect
their market by making such software scarce by going after developers
of what is basicly freeware for patent and trade secret violations
rather than by making the protocol secure by encryption.
--
Dave Emery N1PRE, die@die.com DIE Consulting, Weston, Mass.
PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
