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!