in a pay television system , a program signal is transmitted scrambled to prevent its unauthorized reception , the scrambled signal being accompanied by authorization codes , one for each authorized subscriber , a subscription key and a pay - per - view key . at a receiver , if the appropriate authorization code is received , the receiver functions in the subscription mode in which mode the subscription key provides for the descrambling of the program signal . if the appropriate authorization code is not received , indicating that the subscriber is not pre - authorized to receive the program in an intelligible manner , the receiver is set to function in a pay - per - view mode in which mode , on request , the pay - per - view key provides for the descrambling of the program signal . if there is a delay receiving the appropriate authorization code , the receiver can be set into the pay - per - view mode for at least the period of the delay , so that the scrambled signal is immediately rendered intelligible .