Systems and methods for optical media modification

• US 20040223428A1
• Filed: 02/05/2004
• Published: 11/11/2004
• Est. Priority Date: 12/12/2001
• Status: Active Grant

• Current Assignee: SCA IPLA Holdings Incorporated (Sony Group Corp.)
• Original Assignee: SCA IPLA Holdings Incorporated (Sony Group Corp.)
• Inventors: Hart, John J. III, Howard, Daniel G., Lee, Andrew R., LeVine, Richard B.
• Granted Patent: US 7,643,393 B2
• Time in Patent Office: Days
• US Class Current: 369/47.13
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• CPC Class Codes: G11B 20/00173 wherein the origin of the content is checked, e.g. determining whether the content has originally been retrieved from a legal disc copy or another trusted source
• CPC Class Codes: G11B 20/00586 said format change concerning the physical format of the recording medium
• CPC Class Codes: G11B 20/00659 involving a control step which is implemented as an executable file stored on the record carrier
• CPC Class Codes: G11B 20/00927 wherein said defects or errors are generated on purpose, e.g. intended scratches
• CPC Class Codes: G11B 23/28 Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs write-protect devices for tapes G11B23/042, G11B23/08714; dummy cassettes for locking in the drive G11B33/005
• CPC Class Codes: G11B 23/281 by changing the physical properties of the record carrier
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007

Abstract

Theft, distribution, and piracy of digital content on optical media (software, video, audio, e-books, any content of any kind that is digitally stored and distributed) is often accomplished by copying it directly to another disc using commonly available copy tools and recordable optical media, or the copying of media to another mass manufactured disc. Methods which cause the copy process to become lengthy and inconvenient, or which produce copies that are significantly measurably different from the original and therefore be recognizable as copies, may deter or prevent an unauthorized individual from making copies. In addition, methods which generate an intended slow-down in the read process of the media can be used to authenticate the media at run time. This offers significant advantages to content creators who wish to protect their products.

Claims

1. A method for modifying an optical medium, the medium having a plurality of operational characteristics, each operational characteristic having a predefined limit, comprising:

selecting a region of the medium to be modified; and

modifying the medium in the region according to a predefined limit of a first of the plurality of operational characteristics; and

modifying the medium in the region according to a predefined limit of a second of the plurality of operational characteristics;

such that during a read operation of data stored in the modified region, the read operation is altered in the modified region as a result of the modifications.

2. The method of claim 1 wherein modifying the medium comprises modifying the medium to have a distortion of a size that is approximately the predefined limit of the operational characteristic for distortion size.

3. The method of claim 2 wherein the distortion is formed in a reading layer of the medium through which the optical path is directed.

4. The method of claim 2 wherein the distortion comprises an air bubble formed in the reading layer, a particle deposited in the reading layer, an indentation formed in an outer surface of the reading layer,. or a convex feature formed in an outer surface of the reading layer.

5. The method of claim 2 wherein the distortion is formed in a reflective layer of the medium.

6. The method of claim 1 wherein modifying the medium comprises modifying the medium to have a distortion of a size that is approximately the predefined limit of the operational characteristic for distortion size and wherein the size of the distortion is based on the first size of a physical deformation and a second size of a local corresponding region of increased birefringence.

7. The method of claim 1 wherein modifying the medium comprises modifying the medium to have adjacent distortions that are spaced apart by a length that is approximately the predefined limit of the operational characteristic for length between adjacent distortions

8. The method of claim 1 wherein modifying the medium comprises modifying the medium to have a region of increased birefringence.

9. The method of claim 1 wherein modifying the medium comprises modifying the medium to have a refraction index value that is approximately at the predefined limits of the operational characteristic for range of acceptable refraction index values.

10. The method of claim 1 wherein modifying the medium comprises modifying the medium to have a reflection value that is approximately at the predefined limit of the operational characteristic for reflection value.

11. The method of claim 1 wherein the selected region comprises a data region or a pre-track region of a medium.

12. An optical medium having a plurality of operational characteristics, each operational characteristic having a predefined limit, the optical medium being modified in a modified region according to a predefined limit of a first of the plurality of operational characteristics;

and the optical medium being modified in the modified region according to a predefined limit of a second of the plurality of operational characteristics, such that during a read operation of data stored in the modified region, the read operation is altered in the modified region as a result of the modifications.

13. The optical medium of claim 12 wherein the medium is modified to have a distortion of a size that is approximately the predefined limit of the operational characteristic for distortion size.

14. The optical medium of claim 13 wherein the distortion is formed in a reading layer of the medium through which the optical path is directed.

15. The optical medium of claim 13 wherein the distortion comprises an air bubble formed in the reading layer, a particle deposited in the reading layer, an indentation formed in an outer surface of the reading layer, or a convex feature formed in an outer surface of the reading layer.

16. The optical medium of claim 12 wherein the distortion is formed in a reflective layer of the medium.

17. The optical medium of claim 12 wherein the distortion is of a size that is approximately the predefined limit of the operational characteristic for distortion size and wherein the size of the distortion is based on the first size of a physical deformation and a second size of a local corresponding region of increased birefringence.

18. The optical medium of claim 12 wherein the medium is modified to have adjacent distortions that are spaced apart by a length that is approximately the predefined limit of the operational characteristic for length between adjacent distortions

19. The optical medium of claim 12 wherein the medium is modified to have a region of increased birefringence.

20. The optical medium of claim 12 wherein the medium is modified to have a refraction index value that is approximately at the predefined limits of the operational characteristic for range of acceptable refraction index values.

21. The optical medium of claim 12 wherein the medium is modified to have a reflection value that is approximately at the predefined limit of the operational characteristic for reflection value.

22. The optical medium of claim 12 wherein the selected region comprises a data region or a pre-track region of a medium.