Patent ID: 7783887

Claim:
A method for providing television service to a subscriber, comprising the steps of: receiving descriptor data transmitted over an unsecure medium in a television receiving apparatus of said subscriber, said descriptor data including an identity public key associated with a digital protection system of said television receiving apparatus for transforming data according to a first public/private key encryption algorithm, attribute data identifying television broadcasts which the subscriber is entitled to receive, and a digital signature of said descriptor data by an entity authorizing the subscriber to receive the television broadcasts identified by said attribute data; verifying that said identity public key and said attribute data in said descriptor data have not been altered using said digital signature; providing source test data; performing a first data transformation of a pair of data transformations of said source test data, said pair of data transformations producing resultant test data, said first data transformation being according to said first public/private key encryption algorithm using said identity public key; requesting said digital protection system of said television receiving apparatus to perform a second data transformation of said pair of data transformations of said source test data, said digital protection system including (a) a processor capable of performing said second data transformation according to said first public/private key encryption algorithm; and (b) a permanent data storage accessible only through said processor, said permanent data storage storing an identity private key for performing said second data transformation according to said first public/private key encryption algorithm; comparing said source test data with the resultant test data to verify the identity of said digital protection system; and using said attribute data to access one or more television channels on behalf of said subscriber depending on the results of said verifying step and said comparing step.