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From: DE@GODZILLA.SCH.SYMBOLICS.COM (Doug Evans)
Newsgroups: net.video
Subject: Re:  Satellite Signal Scrambling
Message-ID: <860314131814.6.DE@SHAPIERON.SCH.Symbolics.COM>
Date: Fri, 14-Mar-86 16:18:00 EST
Article-I.D.: SHAPIERO.860314131814.6.DE
Posted: Fri Mar 14 16:18:00 1986
Date-Received: Sat, 15-Mar-86 21:33:47 EST
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    Date:     Fri, 14 Mar 86 10:07:46 CST
    From: Will Martin -- AMXAL-RI <wmartin@ALMSA-1.ARPA>

    I seem to be gathering this impression from this discussion -- that there
    will be a single "code word", to be changed each month, which is to be
    punched into everybody's home top-of-set descrambler to decode HBO. If this
    is true, I can't see how this will ever be workable. There is now a problem
    with BBS's and other info sources (bathroom walls, etc.) contining
    charge card numbers and calling-card numbers, which are used fraudulently
    by some people. If there is one nation-wide "special code number" each month
    for HBO, I predict confidently that, within 4 hours of its being given out
    to the first paying customer, that code number will be posted on BBS's,
    college and office bulletin boards, scribbled on scraps of paper passed
    among co-workers and friends and neighbors, and relayed via phone calls all
    over the nation and to any other areas the satellite footprint reaches.

    Surely there must be more to the descrambling than just expecting
    everyone to honestly pay each month for getting this code-word? 

    Will

No, no, no! - None of the above stuff will ever happen.  This is both
simpler and more high-tech at the same time.  HBO doesn't require that
you do anything at all other than pay your bill and give them some info
on your box.  There is almost no difference between what HBO is doing
and what your local cable company does with premium channels.

The M/A Com boxes are all addressable, just like your cable boxes.  When
you have paid HBO and given them you box serial number, they can then
program their master computer to send a secret code to your own box (via
their satellite link) and enable it.  If you don't pay your bill, they
disable your box from their computer.

Encoding keys are not changed once a month - they are changed every
couple of minutes.  That's part of the digital scrambling process for
the audio.  The video scrambling is the same simple stuff as the cable
companies use right now.

A few people have already broken the scrambling for the video portion of
the signal.  The real challenge will be to decode the audio.