Patent ID: 8300832

Claim:
A method of copy protecting signals flowing between a security module and a receiver via an interface, comprising: receiving a digital signal at a descrambler module of the security module from the receiver via the interface, said digital signal including a scrambled signal; transmitting a copy protection data signal from the receiver to the security module; descrambling the scrambled signal by the descrambler module to obtain a descrambled signal; converting said descrambled signal at the security module into a copy protected signal using the copy protection data signal transmitted from the receiver to prevent the descrambled signal and copies of the descrambled signal from being used without access to and use of the copy protection data signal at the receiver; transmitting the copy protected signal from the security module to the receiver via the interface; and reconverting the copy protected signal to the digital signal in the receiver using said copy protection data signal at the receiver, wherein the use of the digital signal is prevented without access to and use of the copy protection data signal at the receiver, the copy protected signal prevented from being copied without use of the copy protection data signal to remove copy protection, and the copy protected signal is prevented from being used for playing audio-visual information without using the copy protection data signal at the receiver to remove the copy protection from the copy protected signal.