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================= Begin forwarded message =================
From: [email protected] (Peter Trei)
To: [email protected], [email protected]
Subject: Re: VCRPLUS Huffman code
Date: Tue, 05 Sep
> Has anyone worked out the VCRPLUS code?
It was partially broken a few years ago, and the results published in
Cryptologia. I have a xerox in a carton somewhere.
The break was for codes up to 4or 5 digits long, if I recall - this covers
most of the major timeslots on the main stations. Longer codes
cover odd timeslots on less popular stations.
Code which implemented this partial crack was published on the net,
and the VCR+ people got very upset about it - apparently they make
money selling the codes to TV Guide and newspapers. It's protected
as a trade secret, not a patent.
It used a combination of lookup tables and Huffman codes, and
included a certain amount of obfuscation to resist cracking.
Peter
Peter Trei
Senior Software Engineer
Purveyor Development Team
Process Software Corporation
http://www.process.com
[email protected]
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Tobin Fricke (aka LightRay) The Digital Forest BBS (714)586-6142
[email protected] KE6WHF Amateur Radio, 1:103/925 fido