Conditional Access

Conditional Access systems restrict television program access to certain groups of users either because of concerns for privacy or the desire to collect revenue for the service. Providing conditional access requires secure encryption of the program content, secure decryption in a set-top-box for each viewer, and an embedded serial number that is registered in a central conditional access system database. Cable television systems have employed a variety of conditional access systems over the years, many of which have been "broken" by pirates. The newest approach is to embed the decryption technique in a credit-card-sized "point of deployment" module (POD) that can be replaced if the system security is compromised. This approach is much more cost effective than replacing the entire set-top-box.