Patent ID: 6104679
Filing Date: 2000-08-15
Classification: G11B

Abstract:
A method for authenticating an undetermined instance of an Optical Disc as being an original Optical Disc distinct from an unauthorized copy thereof, the undetermined instance selected from the set of all copies of Optical Discs corresponding to original Optical Discs to be authenticated, the method comprising the steps of:recording at least one invalid symbol in a control and data byte on all original Optical Discs to be authenticated, said at least one invalid symbol selected from the group consisting of incorrect symbols, undefined symbols, and ambiguous symbols, said recording being in at least one of the Q-channel components of said control and data byte on said all original Optical Discs to be authenticated;reading the control and data byte of the undetermined instance in said predetermined location;comparing said control and data byte from said reading with said at least one invalid symbol of said recording; anddetermining the undetermined instance to be an original Optical Disc if said control byte from said reading is the same as said at least one invalid symbol of said recording, and determining the undetermined instance to be an unauthorized copy if said control and data byte from said reading is different from said at least one invalid symbol of said recording.