Digital Rights/Restriction Management (DRM)

DRM is also a form of MAC because today it tries to restrict the use of content even if the content has been bought officially (e.g. copy protection). Does it need a TCB as well? DRM is based on cryptography but at some moment the content needs to be decrypted to be played. DRM today goes for a completely protected chain from vendor to device (TCB), where the device enforces the protection. In the future no video screen or audio hardware will be allowed to play protected content without the proper keys provided. (see C't 11/2005, Das nächste windows, schicke optic - totales DRM) and Trusted Platform Modules