Recordable storage medium with protected data area

• US 20010049662A1
• Filed: 04/06/2001
• Published: 12/06/2001
• Est. Priority Date: 06/02/2000
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Linnartz, Johan Paul Marie Gerard, Kalker, Antonius Adrianus Cornelis Maria, Talstra, Johan Cornelis
• Granted Patent: US 6,738,904 B2
• Time in Patent Office: Days
• US Class Current: 705/51
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• 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: 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 20/00094 involving measures which result in a restriction to authorised record carriers
• 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 20/00268 said barcode being recorded in a burst cutting area [BCA]
• CPC Class Codes: G11B 20/00326 the key being embossed on the record carrier
• CPC Class Codes: G11B 20/00384 the key being derived from a physical signature of the record carrier, e.g. unique feature set
• CPC Class Codes: G11B 20/00405 the key being stored by varying characteristics of the recording track, e.g. by altering the track pitch or by modulating the wobble track
• CPC Class Codes: G11B 20/00557 wherein further management data is encrypted, e.g. sector headers, TOC or the lead-in or lead-out areas
• CPC Class Codes: G11B 2020/1259 with ROM/RAM areas

Abstract

The invention relates to a method of storing data on a rewritable data storage medium, to a corresponding storage medium, to a corresponding recording apparatus and to a corresponding playback apparatus. Copy-protective measures require that on rewritable storage media some data must be stored which shall not be modifiable or erasable by consumer end products. A practical problem is the storage of large quantities of such data in a fixed data area. Typically the capacity is limited to a few bits. Meanwhile the amount of copy protection data that needs to be stored may well exceed the storage capacity available in the read-only fixed data area. The invention therefore proposes to write the copy protection data as system data in the recordable data area (4), e.g. as part of the formatting of the medium (1). A cryptographic summary is computed and also stored in the recordable data area (32) or in the fixed data area (2) such that a cryptographic relationship between the fixed data area (2) and the system data area (3) is provided. A playback or replay apparatus will only accept a storage medium with a valid combination of copy protection data and fixed data.

Claims

1. Method of storing data on a rewritable data storage medium comprising a read-only fixed data area and a recordable data area wherein:

system data are stored in the recordable data area,

a cryptographic summary of the system data is generated and stored in the fixed data area and

the cryptographic summary is used for verification of the system data before reading and/or recording of user data.

3. Method as set forth in

claim 1

or

2

, characterized in that a hash function is used for generating the cryptographic summary and for verifying the system data.

4. Method as set forth in

claim 1

or

2

, characterized in that a message authentication code algorithm is used for generating the cryptographic summary and for verifying the system data.

5. Method as set forth in

claim 1

or

2

, characterized in that a key signature algorithm is used for generating the cryptographic summary and for verifying the system data and that a signature is stored as cryptographic summary.

6. Method as set forth in

claim 1

or

2

, characterized in that the cryptographic summary is generated and the system data are stored in the recordable data area as part of the formatting of the storage medium.

7. Method as set forth in

claim 1

or

2

, characterized in that copy protection information is stored as system data, in particular a unique storage medium identifier, a key encrypted by one or more different manufacturer-specific or device-specific keys or one or more lists of revoked devices or revoked storage mediums.

8. Method as set forth in

claim 1

or

2

, characterized in that the system data is originally stored in a corner area of the recordable data area and that during first use of the storage medium in a recording apparatus the system data are copied to a user data area of the recordable data area.

2. Method of storing data on a rewritable data storage medium comprising a read-only fixed data area and a recordable data area wherein:

system data are stored in the recordable data area,

identification data are stored in the fixed data area,

a cryptographic summary of the system data and the identification data is generated and stored in the recordable data area and

the cryptographic summary is used for verification of the system data before reading and/or recording of user data.

9. Storage medium for storing data comprising

a recordable data area in which system data are stored,

a read-only fixed data area in which a cryptographic summary of the system data is stored, the cryptographic summary being provided for verification of the system data before reading and/or recording of user data.

10. Storage medium for storing data comprising

a read-only fixed data area in which identification data are stored,

a recordable data area in which system data and a cryptographic summary of the system data and the identification data are stored, the cryptographic summary being provided for verification of the system data before reading and/or recording of user data.

11. Storage medium as set forth in

claim 9

or

10

, characterized in that the storage medium is a rewritable optical storage medium, in particular a CD or a DVD.

12. Recording apparatus for storing data on a rewritable data storage medium comprising

generating means for generating a cryptographic summary of system data and

recording means for storing the system data in a recordable data area of the medium and for storing the cryptographic summary in a read-only fixed data area of the medium, the cryptographic summary being provided for verification of the system data before reading and/or recording of user data.

13. Recording apparatus for storing data on a rewritable data storage medium comprising

generating means for generating identification data and a cryptographic summary of system data and the identification data and

recording means for storing the cryptographic summary and the system data in a recordable data area of the medium and for storing the identification data in a read-only fixed data area of the medium, the cryptographic summary being provided for verification of the system data before reading and/or recording of user data.

14. Playback apparatus for playback of user data stored on a rewritable data storage medium comprising

reading means for reading system data stored in the recordable data area of the medium and for reading a cryptographic summary of the system data stored in a read-only fixed data area of the medium and

verifying means for generating a cryptographic summary of the system data read from the medium and for verification of the system data by use of the generated cryptographic summary.

15. Playback apparatus for playback of user data stored on a rewritable data storage medium comprising

reading means for reading identification data from a read-only fixed data area of the medium and for reading system data and a cryptographic summary of the system data and the identification data from a recordable data area of the medium and

verifying means for generating a cryptographic summary of the system data and the identification data read from the medium and for verification of the system data by use of the generated cryptographic summary.