Newsgroups: sci.crypt
Path: msuinfo!galaxy.cps.msu.edu!gurney
From: gurney@galaxy.cps.msu.edu (Eddy J. Gurney)
Subject: Re: VCR+ code question: Was it cracked and legal action taken?
Message-ID: <1992Jan7.033234.27832@msuinfo.cl.msu.edu>
Originator: gurney@galaxy.cps.msu.edu
Sender: news@msuinfo.cl.msu.edu
Reply-To: gurney@galaxy.cps.msu.edu (Eddy J. Gurney)
Organization: Dept. of Computer Engineering, Michigan State University
References: <1992Jan6.160219.3580@msuinfo.cl.msu.edu> <undHjkyu4@cs.psu.edu>
Date: Tue, 7 Jan 92 03:32:34 GMT

In article <undHjkyu4@cs.psu.edu> so@babel.cs.psu.edu (Nicol C. So) writes:
>Could somebody briefly explain to me what the VCR+ code scheme is about?
>Specifically, what is being encrypted?  How do the cryptograms look like?
>Why is it used at all?

The VCR+ code scheme is used by a small device which transmits IR codes
to your VCR and/or cable box at various times of the day to record whatever
programs you tell it to.  The way you tell it which program to record
is through a 1 to 8 digit number, which is published in the TV books
and newspapers of a number of cities around the US (and maybe
elsewhere?) This code is "converted" to date, time, channel and length,
and when the appropriate events occur, the VCR+ unit transmits codes to
turn power on, set the channel, start recording, stop recording, turn
power off, etc.

A one-time set up is required, which not only tells the device the make
of your VCR and/or cable box, but also how the channels correspond to an
internal look up table.  That is, in the beginning of the TV book, there
is a list of all the popular channels, along with the "VCR+ channel".  For
instance, HBO might be assigned 38, and local channel seven, 7.  The local
newspaper then uses this lookup to create the code mentioned above, and
publishes it for all VCR+ users to use.

For example, lets say I want to record Quantum Leap this Wednesday on NBC.
I would enter code "4866" into the VCR+ gizmo, and it will take care of
everything else.  (Just for the info, that translates to local channel 4
[also VCR+ "channel" 4], on Wednesday, January 7, from 10pm to 11pm.)

A nice idea, but it would be very useful to know their encryption scheme!

Hope that helps. :-)

Best regards,
Eddy

P.S. Hey Phil-- if you're interested in taking a look at this (I hope you
     are! :-) let me know and I'll see if I can't dig up the source to
     the code that worked for codes of 4 digits or less...

-- 
         Eddy J. Gurney  N8FPW       THE ECCENTRICITY GROUP           EEEEGGGG
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   (Preferred)          (If cps bounces)      (If you HAVE to :-)     EEEEGGGG
--
   "Failures are divided into two classes-- those who thought and never did,
         and those who did and never thought."     John Charles Salak
