RECORD CARRIER WITH COPY PROTECTION MEANS

摘要

In summary, ROM marks (such as wobbles, lateral deviations in the spiral with lands and pits in an optical disc) are used on optical media to ensure consumer-grade copying devices cannot duplicate original media. An additional level of security is that the detection of the side channel information requires knowledge of a certain secret, which must be hidden well in authorized players. If the secret leaks, a professional pirate will be able to detect the ROM mark and duplicate the original medium with the side channel information intact. The present invention proposes that instead of a single ROM mark, many ROM marks are applied to a disc. Further, devices are divided into groups, and each group has the capability to only detect one mark from the group. This way, if a secret is obtained from a device, the disc can be duplicated, but only a limited number of devices will be able to use this disc. Creating a disc that can be played in any device requires the hacking of one device from every group.