Method for utilizing medium nonuniformities to minimize unauthorized duplication of digital information

• US 5,412,718 A
• Filed: 09/13/1993
• Issued: 05/02/1995
• Est. Priority Date: 09/13/1993
• Status: Expired due to Fees

• Current Assignee: Kent Ridge Digital Labs
• Original Assignee: Institute of Systems Science (The National University of Singapore Society)
• Inventors: Wang, Weiguo, Kankanhalli, Mohan S., Narasimhalu, Arcot D.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/120,969
• Time in Patent Office: 596 Days
• Field of Search: 380/4, 380/44-47
• US Class Current: 705/51
• CPC Class Codes: G06F 21/80 in storage media based on magnetic or optical technology, e.g. disks with sectors preventing unauthorised reproduction or copying of disc-type recordable media G11B20/00
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• 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 20/00188 involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00246 wherein the key is obtained from a local device, e.g. device key initially stored by the player or by the recorder
• CPC Class Codes: G11B 20/00253 wherein the key is stored on the record carrier
• CPC Class Codes: G11B 20/00326 the key being embossed on the record carrier
• CPC Class Codes: G11B 20/00949 said intentional errors occurring due to bad sectors, which are either physically destroyed or which are declared defective in the defect management information
• CPC Class Codes: G11B 20/00963 wherein said defects or errors are not generated on purpose, e.g. random defect patterns occurring during the normal manufacture
• CPC Class Codes: G11B 20/1816 Testing

Abstract

The present invention is a method for preventing unauthorized copying and use of information which is stored on a storage medium and for restricting the use of such information to designated devices. Copy protection is achieved by generating a signature from a given storage medium. The signature is derived from an arbitrarily selected list of nonuniformities, uniformities and their attributes. The selected list may contain nonuniformities at any granularity level. As such, this signature is unique to a given storage medium in the same way finger prints are unique to a human being. This signature is used to derive a key for encrypting the information on the storage medium. Any copying of the distribution information from one storage medium to another results in the mutation of the signature required to decrypt the information. Therefore, the present invention obviates the need for introducing artificial indica or requiring a special hardware subsystem for achieving a copy protection scheme.

Restricting the usage of information on a distribution medium to a designated device is achieved by verifying the device ID (DID-D) of the device with the device ID (DID-S) stored in the distribution medium before the decryption and transfer of information are undertaken. Decryption of the information is accomplished by generating a key from both the signature of the distribution medium and the DID-S.

Claims

1. In a system for distributing information including at least a storage medium and at least an output device, said information including both distributed information (DI) and supporting information (SI), a method for preventing unauthorized use of said information on said storage medium, said storage medium having nonuniformities and uniformities, said method comprising the steps of:

generating a signature from the nonuniformities of said storage medium without introducing any artificial indica on the medium;

incorporating said signature into an encryption key and encrypting said information prior to distributing said storage medium;

permitting access to said storage medium by said device in response to verification of said signature; and

generating a decryption key with said signature for decrypting said information and permitting access to said information by said device.

2. The method as defined in claim 1, wherein said information comprises any digital information.

3. The method as defined in claim 1, wherein said information is encrypted in part or in total.

4. The method as defined in claim 1, wherein said signature is function of a list which comprises of said nonuniformities, uniformities and their attributes.

5. The method as defined in claim 4, wherein said list comprises a subset of all of said nonuniformities, uniformities and their attributes.

6. The method as defined in claim 5, wherein said subset is arbitrarily selected.

7. The method as defined in claim 5, wherein said subset is selected non arbitrarily.

8. In a system for distributing information including at least a storage medium and at least a designated device, said device having an unique identification (ID) number, said information including both distributed information (DI) and supporting information (SI), a method for preventing unauthorized use of said information on said storage medium, said storage medium having nonuniformities and uniformities, said method comprising the steps of:

generating a signature from the nonuniformities of said storage medium without introducing any artificial indica on the medium;

incorporating said signature and said device ID into an encryption key and encrypting said information prior to distributing said storage medium;

permitting access to said storage medium by said device in response to verification of said signature and said device ID; and

generating a decryption key with said signature and said device ID for decrypting said information and permitting access to said information on said device.

9. The method as defined in claim 8, wherein said information comprises any digital information.

10. The method as defined in claim 8, wherein said information is encrypted in part or in total.

11. The method as defined in claim 8, wherein said signature is a function of a list of said nonuniformities, uniformities and their attributes.

12. The method as defined in claim 11, wherein said list is a subset of all of said non uniformities, uniformities and their attributes.

13. The method as defined in claim 12, wherein said subset is arbitrarily selected.

14. The method as defined in claim 12, wherein said subset is selected non arbitrarily.