SYSTEM FOR TRANSFERRING CONTENT INFORMATION AND SUPPLEMENTAL INFORMATION RELATING THERETO

摘要

A system for copy protecting content information has an arrangement for receiving and controlling the playback of encoded video. The video content, e.g. MPEG compressed digital video, is watermarked and includes a control signal indicating the status (e.g. playback only, one generation of copy allowed, etc). In the receiver device a check is performed to allow playback in dependence of the watermark. The watermark is extracted in a separate decoder device, such as an external MPEG decoder. The receiver device starts the playback via the external decoder, and the separate decoder communicates retrieved watermark information via a link to the playback device. The playback device checks the watermark information against further supplemental information, such as a physical mark on the record carrier or the control signal. Said communication may be protected by cryptographic methods, such as a digital signature.