Access control system in a data broadcasting system

摘要

Disclosed is a method and apparatus for enabling an authorized receiver station to decrypt encrypted information broadcast by a transmitter station, and for decrypting the information within the authorized receiver station. The method includes steps of storing a predetermined Subscription Key value in the authorized receiver station and, using the predetermined Subscription Key value, generating a Decryption Key value. In a next step the transmitter station broadcasts a signal which includes the encrypted information. After the broadcasted signal is received at the authorized receiver station, the authorized receiver station performs a predefined algorithm. The predefined algorithm uses the generated Decryption Key value to decrypt the encrypted information from the received signal.