A conditional access control apparatus for inserting descrambling messages and impulse authorizations to enable requesting subscribers to utilize requested scrambled content. The apparatus includes a content and asset storage module for storing content and assets, and a pre-encryption module for encrypting...http://www.google.de/patents/US7975280?utm_source=gb-gplus-sharePatent US7975280 - Method and apparatus for performing impulse authorizations within a video on demand environment
