[sci.electronics] Videocipher 2 cracked?

john@anasaz.UUCP (John Moore) (08/07/89)

Background: The VideoCipher 2 (TM General Instruments) is sold as
an authorized unscambler allowing consumers to watch encrypted
satellite TV signals. It uses DES encryption for key management,
and each unit comes with a unique set of internal DES keys that
are known to the authorizer. Programs are transmitted with the
audio information and the sync information encrypted using
a pattern that is based on a "program key". This key is
broadcast regularly, encrypted in the "monthly master key"
for the program source. The monthly master key is transmitted
regularly encrypted in the DES key for each AUTHORIZED unit,
allowing that unit to decrypt the program key and then get
the actual key for the pseudo-random bit sequence. [I hope
I have this right].

There have been reports of people selling "magic" versions of
this box that receive all channels. In fact, several of these
folks were arrested last year here in Phoenix. I know of one
technique that used to work - you could reprogram the uC
that decided when to use the program keys so that it would try
it on all channels. Since all (?) programs used to be sent with
the same program key or monthly master key, this used to be
feasable. However, presumably now they use different keys for different
program sources.

The DES keys and algorithm themselves are kept in RAM in a
battery backed up MCU, so that they are very difficult to get
at.

QUESTIONS:
(1) What are the other techniques for cracking this thing. [no - I
don't want to do it - my VC-II is just fine with me paying for
what I watch - I'm just curios]. Presumably they don't require
breaking DES, so I wonder how they do it. You would think that
MACOM (the original developer of the box) would know how to
make it commercially secure. By that, I mean that while a determined
hacker could crack one box, he/she would not be able to
crack enough boxes easily enough to make it commercially worth
while.

(2) I have heard that export of this device is illegal, and that
drug smuggling planes would sometimes return back south with
VC-II's on board. Is this true? Are they still illegal? How
do the various cable and private systems in Mexico, Carribean, etc
watch HBO, CNN, etc?
-- 
John Moore (NJ7E)           mcdphx!anasaz!john asuvax!anasaz!john
(602) 861-7607 (day or eve) long palladium, short petroleum
7525 Clearwater Pkwy, Scottsdale, AZ 85253
The 2nd amendment is about military weapons, NOT JUST hunting weapons!