Access control system in a data broadcasting system

Invention Patent: <B> "DIFFUSION DATA ACCESS CONTROLLER COMMUNICATION SYSTEM" <D>. a method and apparatus is disclosed for allowing an authorized receiving station to decrypt encrypted information broadcast by a transmitting station and for decrypting information within the authorized receiving station. The method includes the steps of storing a predetermined Subscription Key value at the authorized receiving station and using the predetermined Subscription Key value, generating a Decryption Key value. In a next step, the transmitting station broadcasts a signal that includes the encrypted information. After the broadcast signal is received at the authorized receiving station, the authorized receiving station executes a predefined algorithm. The predefined algorithm uses the Decryption Key value generated to decrypt the encrypted information of the received signal.