IMPROVEMENTS IN OR RELATING TO THE COPY PROTECTION OF OPTICAL DISCS

摘要

The more effective is the copy protection provided on a DVD, the greater is the likelihood that the copy protection will adversely interfere with legitimate uses of the disc. In a disc where the content is arranged in physical sectors, it is now proposed to provide subversive regions on the disc having a similar structure to genuine regions. A subversive region and a genuine region will each extend over one or more physical sectors. The subversive region will be provided with physical sector addresses which coincide with addresses of the genuine region. Navigational data will ensure that it is the genuine, rather than the subversive, region which will be accessed during normal play, but the subversive region will effectively hide the genuine region during copying.