Patent ID: 7571451
Filing Date: 2009-08-04
Classification: H04N

Abstract:
1. In a video-on-demand conditional access information distribution system comprising provider equipment for providing video-on-demand programs to subscribers via an in-band communications channel, a method comprising the steps of: establishing a session with a set top terminal including defining the in-band communications channel for transporting content to said set top terminal; communicating to said set top terminal, via said defined in-band communications channel, an authorization message and a descrambling message suitable for determining a descrambling key for descrambling a program stream; scrambling said program stream provided to a set top terminal via said defined in-band communications channel to produce a scrambled program stream; including, within said program stream being scrambled, video-on-demand content requested by said set top terminal; sending, prior to said set top terminal receiving said descrambling message and said requested content, said authorization message; storing said authorization message at said set top terminal; and deriving a descrambling key from said stored authorization message and the descrambling messages.