conditional access module (digital TV) (CAM)

Conditional Access Modules(CAM) are decryption devices for pay TV. Each encrypted transmission method requires its own CA module, which is built into or plugged into the set-top box.

The set-top box has a card reader or a standardized interface for the CA modules.

CAM module from Irdeto for a set-top box

There are also PC cards with an integrated Common Interface( CI) into which a CA module can be inserted. The PC card passes the encrypted data stream via the Common Interface to the CA module, which decrypts the TV data. These can then be further processed, played back or recorded.