Method and apparatus for performing session based conditional access

Abstract

The disadvantages heretofore associated with the prior art are overcome by the present invention of a method and apparatus for enabling session-based conditional access to on-demand content of variable duration.

What is claimed is:  
     
         1 . In an information distribution system utilizing conditional access, a method comprising the steps of: 
 scrambling a program stream provided to a set top terminal via a defined communications channel;    communicating to said set top terminal while establishing a session, via one of said defined communications channel and an out-of-band communications channel, an authorization message and descrambling message suitable for determining a descrambling key for descrambling said program stream; and    including, within said program stream being scrambled, content requested by said set top terminal.    
     
     
         2 . The method of  claim 1 , wherein said defined channel comprises a quadrature amplitude modulated (QAM) channel and said program stream comprises an MPEG transports stream.  
     
     
         3 . The method of  claim 1 , further comprising the steps of: 
 communicating to said set top terminal, via one of said defined communications channel and said out-of-band communications channel, a de-authorization message, said de-authorization message being communicated in response to a session terminating event.    
     
     
         4 . The method of  claim 3 , wherein said session terminating event comprises one of a session termination request being received from said subscriber and a period of subscriber inactivity exceeding a predetermined time interval.  
     
     
         5 . The method of  claim 1 , wherein said authorization message and descrambling message are communicated to said subscriber after said content is included in said scrambled program stream, said method further comprising the step of: 
 repeating, for a predetermined period of time, said step of communicating said authorization message and descrambling message to said subscriber    
     
     
         6 . The method of  claim 1 , wherein said information distribution system comprises an information on demand system.  
     
     
         7 . In conditional access information distribution system comprising provider equipment for providing information to subscribers via a communications channel, a method comprising the steps of: 
 scrambling a program stream provided to a set top terminal via a defined communications channel;    communicating to said set top terminal, via one of said defined communications channel and an out-of-band communications channel, an authorization message and descrambling message suitable for determining a descrambling key for descrambling said program stream; and    including, within said program stream being scrambled, content requested by said set top terminal.    
     
     
         8 . The method of  claim 7 , wherein said defined channel comprises a quadrature amplitude modulated (QAM) channel and said program stream comprises an MPEG transports stream.  
     
     
         9 . The method of  claim 7 , further comprising the steps of: 
 communicating to said set top terminal, via one of said defined communications channel and said out-of-band communications channel, a de-authorization message, said de-authorization message being communicated in response to a session terminating event.    
     
     
         10 . The method of  claim 9 , wherein said session terminating event comprises one of a session termination request being received from said subscriber and a period of subscriber inactivity exceeding a predetermined time interval.  
     
     
         11 . The method of  claim 7 , wherein said authorization message and descrambling message are communicated to said subscriber after said content is included in said scrambled program stream, said method further comprising the step of: 
 repeating, for a predetermined period of time, said step of communicating said authorization message and descrambling message to said subscriber    
     
     
         12 . The method of  claim 7 , wherein said conditional access information distribution system comprises an information on demand system.  
     
     
         13 . In conditional access information distribution system comprising provider equipment for providing information to subscribers via a communications channel, provider apparatus comprising: 
 a conditional access system, for scrambling a program stream to produce a scrambled program stream; and    a session manager, for providing said scrambled program stream to a set top terminal via a defined communications channel, said session manager including within said scrambled program stream content requested by said set top terminal;    said session manager communicating to said set top terminal, via one of said defined communications channel and an out-of-band communications channel, an authorization message and descrambling message suitable for determining a descrambling key for descrambling said program stream;    said conditional access system providing said authorization message and said descrambling message to said session manager.    
     
     
         14 . The provider apparatus of  claim 13 , further comprising an information server, for providing said requested content to said session manager.  
     
     
         15 . The provider apparatus of  claim 13 , wherein said defined channel comprises a quadrature amplitude modulated (QAM) channel and said program stream comprises an MPEG transports stream.  
     
     
         16 . The provider apparatus of  claim 13 , wherein: 
 said session manager, in response to a session terminating event, communicates a de-authorization message to said set top terminal via one of said defined communications channel and said out-of-band communications channel.    
     
     
         17 . The provider apparatus of  claim 16 , wherein said session terminating event comprises one of a session termination request being received from said subscriber and a period of subscriber inactivity exceeding a predetermined time interval.  
     
     
         18 . The provider apparatus of  claim 13 , further comprising: 
 a data storage module, coupled to the information server, for storing content.