METHOD OF PREVENTING UNAUTHORIZED DUPLICATION OF OPTICAL DISC BY PHYSICAL AUTHENTICATION, MANUFACTURING PROCESS OF SUCH OPTICAL DISC AND OPTICAL DISC THUS OBTAINED

摘要

The invention proposes to prevent unauthorised duplication of optical discs, in particular in compatibility with all existing readout hardware devices by creating, during the manufacturing process, at least one limited predefined portion (33) in the reflective layer (30) with an absence of reflectivity, and by granting access to digital content only when an identified absence of reflectivity is detected. The reflective layer (30) is transformed before or just after being bonded to a standard dummy substrate, the portion(s) (33) extending over a plurality of tracks of the data layer in which data are stored. As an example, a specific temporary cover (110) with missing physical portions (111) is set on with the reflective sputtered layer (30) and a chemical agent (35) is then released in the missing physical portions (111). The reflective layer is then locally removed to form openings locations (33) directly in regard to the corresponding area of the missing portions (111), and the temporary cover (110) is then set away. Application to CD and DVD write once discs, rewritable discs, dual discs, one sided or dual sided optical discs.