Patent ID: 8243927

Claim:
A set top box (STB) for receiving a stream including scrambled programs, entitlement control messages (ECM) including information about the scrambled programs, and entitlement management messages (EMM) including information about the subscriber, the STB descrambling the scrambled programs, and reproducing the descrambled programs for a subscriber based on a permission program from a vendor, the STB comprising: a programmable decryption chip receiving the ECM and the EMM; a descrambler receiving the scrambled programs; and a video output controller reproducing the descrambled programs, wherein the STB is manufactured such that the programmable decryption chip does not include the permission program of the vendor, wherein subsequent to manufacturing of the STB, the programmable decryption chip downloads and executes the permission program from the vendor, the permission program having instructions from the vendor for extracting the ECM and EMM from the stream, and decrypting an encrypted scramble key based on the extracted ECM and EMM, and wherein the descrambler descrambles the scrambled programs based on the decrypted scramble key and transmits the descrambled programs to the video output controller for reproduction, and subsequent to downloading and executing the permission program from the vendor, the programmable decryption chip downloads and executes an other permission program from an other vendor, the other permission program having instructions from the other vendor for extracting the ECM and EMM from the stream, and decrypting an encrypted scramble key based on the extracted ECM and EMM.