Patent attributes
A copy deterrent is provided for an audiovisual product (400) such as a DVD-video format optical disk. User identities are allocated to each of a plurality of users. The audiovisual product (400) is then recorded including, for each allocated user identity, a section of playback content (421) unique to that allocated user identity, e.g. a video object (VOB) which prominently displays personal data of the user (such as their name) or which contains a discrete digital watermark. The user enters a user identity code (80) upon playback and the recorded audiovisual product (400) is reproduced including selecting a corresponding section of the unique playback content according to the received user identity. A single version of the disk is recorded and sent to all users, but playback is personalised to each of the users individually. This is a strong deterrent against copying of the audio and video playback e.g. with a VCR or other recording device.
