A copy prevention method and apparatus for a digital video system is disclosed including the steps of: (a) adding a header area of a header start code and key field to a reproduced bit stream; (b) decrypting and transmitting the bit stream to which the header area is added; (c) detecting a key field...http://www.google.com/patents/US6028932?utm_source=gb-gplus-sharePatent US6028932 - Copy prevention method and apparatus for digital video system
