Key distribution system for digital video signal

Although the traditional analogue video signal has served the information broadcasting network effectively, its drawbacks make its usage limited. With the advent of the digital video signal and the use of modern compression techniques the quality of the digital programmes was improved. Once extra programmes such as feature films became available, their providers needed to be paid, and a conditional access system had to be found of financing these programmes. Compressed digital video signal needs new scrambling methods and a key distribution system for conditional access, copyright protection and finance. This paper suggests some digital scrambling tools and the design of an efficient and realistic key distribution system for digital video information broadcasting and any other environment in which the MPEG-2 bit stream is employed. The scrambling methods and the key distribution system discussed are based on the format of the transport stream packet of the MPEG-2 transport layer