Data protection system

Recorded material on an optical disc comprising digital data segmented into consecutive sectors each containing encrypted data, the data in each sector being encrypted using a unique key, the unique key for each sector being dependent upon the logical block address on the disc corresponding to the start of each sector.

Optical disc player software containing embedded within its code the logical block address on the disc of the first sector corresponding to a file or track, decryption software operated by a key and an algorithm for determining the unique key for each sector from the logical block address corresponding to the start of that sector.

A method of reading encrypting digital data from a disc comprising the steps of (a) decrypting data in consecutive sectors each using a unique key (b) the unique key for each sector being dependent upon the logical block address on the disc corresponding to the start of that sector.

A method of preventing a computer copying audio sessions on an optical disc including the steps of (a) describing the audio session as data tracks in the Table of Contents contained within the Q-channel information in the lead in area of the disc, (b) describing the audio session in the Q-channel data in each sector within the session as audio tracks.

A method of monitoring whether a disc according to the invention is being accessed in an authorized way comprising the steps of (a) including software for a supervisory program on the said disc (b) activating this supervisory program when the computer operating system first accesses the disc, (b) insertion of all or part of the supervisory program into the operating systems driver chain that allows two way communication between an application program accessing the disc and the disc drive (d) using the supervisory program to monitor communications between the said application program and the disc drive.

A method of manufacturing digital data storage medium comprising the steps of:

• (a) segmenting copyright material in digital form into consecutive segments (b) allocating each segment to a sector of the storage medium (c) pre-determining the position of each sector on the storage medium and using an algorithm to derive a unique encryption key for each sector according to the logical block address corresponding to the start of each sector (d) encrypting each sector using its unique key, and (d) writing the encrypted data sectors to the said storage medium.

A method of reading encrypting digital data from a storage medium comprising the steps of (a) decrypting data in consecutive sectors each using a unique key (b) the unique key for each sector being dependent upon the logical block address on the storage medium corresponding to the start of that sector.

A method of monitoring whether a storage medium according to the invention is being accessed in an authorized way comprising the steps of (a) including software for a supervisory program on the storage medium (b) activating this supervisory program when the computer operating system first accesses the storage medium, (b) insertion of all or part of the supervisory program into the operating systems driver chain that allows two way communication between an application program accessing the storage medium and a storage medium read/write unit (d) using the supervisory program to monitor communications between the said application program and the storage medium read/write unit.