VideoCipher 2

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 the primary encryption scheme used by major cable TV programmers to prevent TVRO owners from receiving free terrestrial television programming. It was especially notable due to the widespread compromise of its encryption scheme.

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.

In the mid 1980s HBO, Cinemax and several other cable providers were facing an uphill battle trying to prevent owners of TVRO equipment from viewing what were at the time free over the air signals. In an effort to prevent a growing number of homes from viewing the channels for free, HBO in January 1986, decided to begin scrambling their satellite signals.

There are several variants of the Videocipher scrambling system:

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.

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