Embedded Conditional Access (CA) systems
Embedded CA systems are predominantly used in digital television. These are based on three concepts:
Conditional Access Module (CAM)
Access with the aid of such modules functions in a similar way to that with embedded CA systems. However, the smart card is first plugged into a hardware module, which is then connected with the receiver unit via the so-called Common Interface (CI).
The advantage of using a CAM is the possibility to quickly change the encryption system. The coverage of interactive services which incur fees could expand. CI-interfaces are lacking in many receiver devices due to the high hardware costs.
Software-based systems for digital rights (DRM)
In principle, DRM systems, which are familiar from computers, can also run on iTV devices. Connection takes place with the aid of a software key and a licence which is requested via the return channel. This method appears simple and flexible for use with the contents of iTV applications. Dispensing with a smart card does unfortunately make this system less secure.