From: paul@poboy.b17c.ingr.com (Paul Robichaux)
Date: Thu, 14 Apr 94 06:06:45 PDT
To: habs@warwick.com (Harry Shapiro Hawk)
Subject: Re: Tech: Encryption and Satellites (re: GI)
In-Reply-To: <9404131331.AA03139@warwick.com>
Message-ID: <199404141305.AA09379@poboy.b17c.ingr.com>
MIME-Version: 1.0
Content-Type: text/plain


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> Key pay cable providers are now going though the second stage
> of moving from General Instrument's Video Cipher II (VC II)
> encryption system to its more secure VideoCipher Renewable 
> Security (VCRS) system.

VCII and VCII+ both use DES. VC/RS uses a plug-in card; right now the
RS cards are all still DES. An interesting note is that the VC family
uses digital sound and encrypts it. You can allegedly reconstruct the
vertical sync signal and get watchable pictures, but for sound you
either need to break DES or exploit a system vulnerability.

> Adopting VCRS are HBO, Cinemax, Showtime, TMC, Viewer's choice,
> REquest TV, Playboy channel, Spice, and Netlink. Netlink offers
> three superstations.

All of the above are presently VCII+ customers.

There were several such design and implementation vulnerabilities in
the VCII system, and they were quickly exploited by pirates. As a
counter, GI introduced the VCII+, which has fewer vulnerabilities and
has not yet (AFAIK) been "broken". (n.b. I know that the use of
"wizard codes", or master keys, still continues, but I don't really
count that as a break.)

> "There have been 30,000 to 40,000 conversion customers
> a month for the past for months."

Part of the reason behind the conversion is necessity. Programmers
were downlinking both VCII and VCII+ authorization datastreams for a
while. When VC/RS became available, some programmers switched over to
downlinking VCII+ and VC/RS. When the VCII+ datastreams go dark, VCII+
descramblers won't work.

> Meanwhile, with the digital era in mind, Primestar Partners
> is preparing to move its DBS (direct broadcast satellite)
> from Scientific-Atlanta's analog B-Mac encryption to 
> General Instrument's DigiCipher digital compression
> technology, which also provides teh most recent security
> meansures.

GI has been very, very tightlipped about any of the compression or
encryption technology behind DigiCipher.

- -Paul

- -- 
Paul Robichaux, KD4JZG      | Out the 10Base-T port, through the router, 
perobich@ingr.com           | over the leased line, off the bridge, past
Intergraph Federal Systems  | the firewall... nothing but net.
	       Of course I don't speak for Intergraph.

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