VideoCipher is a brand name of analog scrambling and de-scrambling equipment for cable and satellite television invented primarily to enforce Television receive-only (TVRO) satellite equipment to only receive TV programming on a subscription basis. The second version of Videocipher, Videocipher II, was especially notable due to the widespread compromise of its encryption scheme.
Background
Satellite providers Through the first half of the 1980s, HBO, Cinemax and other premium television providers with analog satellite transponders faced a fast growing market of TVRO equipment owners. Satellite television consumers could watch these services simply by pointing their dish at a satellite, and tuning into the provider's transponder. Two open questions existed about this practice: whether the Communications Act of 1934 applied as a case of "unauthorized reception" by TVRO consumers; and to what extent it was legal for a service provider to encrypt their signals in an effort to prevent its reception. The Cable Communications Policy Act of 1984 clarified all of these matters, making the following legal:
Reception of unencrypted satellite signals by a consumer Reception of encrypted satellite signals by a consumer, when they have received authorization to legally decrypt it This created a framework for the wide deployment of encryption on analog satellite signals. It further created a framework (and implicit mandate to provide) subscription services to TVRO consumers to allow legal decryption of those signals. HBO and Cinemax became the first two services to announce intent to encrypt their satellite feeds late in 1984.
Videocipher technology Videocipher was invented in 1983 by Linkabit Corporation (later bought out by M/A-COM in 1985, operated as M/A-COM Linkabit). In the mid 1980s, M/A-COM began divesting divisions which fell outside their core RF & Microwave component and subsystem products. The Linkabit division was acquired by General Instrument in 1987. Videocipher was used throughout the 1990s by RCTI and SCTV to encrypt some foreign programs (such as sports events and movies) as part of the term of their rights, to prevent overseas access so that the programs could only be accessed through the RCTI and SCTV networks via UHF/VHF frequency in Indonesia. Indovision also used Videocipher to encrypt their channels as a counteract against piracy between 1994 and 1997.
Variants There were several variants of the Videocipher scrambling system:
Videocipher I This was the first version of the Videocipher system that was first demonstrated by Linkabit in 1983. Also known as Videocipher IB, this variation on Videocipher was commonly used by sports backhauls. CBS used this system from 1987 to the mid-1990s to encrypt its transmissions to affiliates on the Telstar 301 and Telstar 302 satellites. In Canada, the CTV television network also used this technology on its network feeds. With this system the video is scrambled by means of re-ordering the video scan lines, while all audio remains in the clear. This system was in use as late as the early 2000s. Videocipher I (VCI) system was initially considered for use by HBO in the 1980s. HBO tested VCI extensively, but was ultimately rejected in favor of Videocipher II. HBO's use of VCI would have required descramblers for home satellite viewers. Due to costs involved with VC1, maintaining VCI a descrambler was determined to be too expensive for consumer use. PBS in the USA used VideoCipher I on its satellite feeds to its member stations in the mid-80s to take advantage of the high-fidelity digital audio capability offered by VCI. This was desirable for some of the programming PBS would air in that era, such as classical concerts and other musical programming, some of which were simulcast by partnering public radio stations using the same audio feed. PBS had attempted in 1979 to send its program audio digitally to its member stations using a system called DATE (Digital Audio for TElevision), which used the existing analog video's vertical blanking interval (VBI) to send digital audio. VCI provided this same feature while freeing up the VBI for other purposes like closed-captioning and teletext, making DATE obsolete by the mid-1980s (however, DATE did offer 4 channels of audio as opposed to VideoCipher I's 2-channel stereo). The Leitch Viewguard scrambling system used for satellite feeds as well used the same video line re-ordering as well, while also leaving the audio intact. ABC and Fox used Viewguard as well on their analog network feeds to their affiliate stations shortly before switching to digital satellite distribution in 2005 (for ABC) and 2004 (for Fox).
Videocipher II
Videocipher II was the first consumer TVRO scrambling system. HBO and Cinemax, which had transponders on Satcom 3R and Galaxy 1, began encrypting their west coast feeds services with Videocipher II 12 hours a day early in 1985, then did the same with their east coast feeds by August. The two networks began scrambling full time on January 15, 1986, which in many contemporary news reports was called "S-Day". Within two years, encryption through Videocipher II was used by a majority of major cable television programmers. However, lapses in its security enabled some pirate decryption, modifying a consumer descrambler to receive free programming. Beginning in 1991, programmers began to phase out the VCII system in favor of the more secure Videocipher II Plus (RS) system. The system was fully phased out in 1993. Originally sold as a stand-alone decoder box that consisted of a fully electronic decoder and descrambler module, other satellite system manufacturers began to make their receivers with the GI descrambler module installed. This VCII system digitally encrypts stereo audio using the DES encryption scheme and scrambles video by inverting the video polarity and moving color information to a nonstandard area frequency. It is noteworthy that the Videocipher II Plus design did not alter the video scrambling scheme (only the audio encryption was improved). As such, a Videocipher II decoder is still capable of decoding the video portion of a Videocipher II Plus encrypted stream. In the late eighties and early nineties, VideoCipher II modules that had been pirated, began to receive constant Electronic Counter Measures (ECM).
… excerpt ends here. Continue reading the full article.
