The BBC Select decoder

Describes a conditional access TV system specifically developed for the BBC to make use of their night time period when normal programmes are not being transmitted. The service launched in 1992 targets special interest groups such as lawyers, doctors, ethnic minorities etc. and is called BBC Select. The system is based on the VideoCrypt philosophy using a smart card based detachable conditional access system. The three new components to add to a typical head-end installation to support the BBC Select service are the subscriber management system which handles all the customer related data, a security computer which performs the encryption of the transmitted data, and finally the encoder which performs the scrambling of the video and inserts the data in the video. The decoder performs the inverse function of the encoder i.e. descrambling and decryption and is a highly integrated architecture with the descrambling process being carried out in a specially developed ASIC and the decryption being carried out by a smart card