Patent ID: 7706661

Claim:
A method of copy protecting an optical disc having a capacity greater than that of a standard compact disc and carrying content and control data, wherein the content is arranged in one or more content files and the control data is arranged to control access to the content files, the method comprising: providing a control data structure utilised during play of the content on the disc and including a title and a program chain; providing a redundant control data structure which cannot be utilised during play of the content on the disc and having no pointers thereto in the control data structure wherein the redundant control data structure includes at least one of a title or a program chain; incorporating errors into the redundant control data structure, wherein the errors are arranged to frustrate access to the content files by way of the control data for copying the content files and are not accessed during normal play of the copy protected optical disc by a player of standard type and are accessed by a device copying the copy protected optical disc.