A conditional access method and apparatus for use with a system for controlling of digital TV program start time. Subscriber access is authorized to digital program streams. Content are divided into a plurality of working periods. Each working period of the plurality of working periods is scrambled with...http://www.google.de/patents/US7809942?utm_source=gb-gplus-sharePatent US7809942 - Conditional access method and apparatus of a receiver system for controlling digital TV program start time
