US Patent 7925020 Apparatuses and methods for copy protection

Apparatuses and methods may include creating at least one of a scramble key and a descramble key using a Copy Protection (CP) key that existed prior to a refresh period and using a value created at a time associated with the changing of a channel during the refresh period, and using the at least one of the scramble key and the descrambled key until the CP key is refreshed at an end of the refresh period.