Authenticating a data storage medium using predetermined inter-sector realationships

• US 20040168025A1
• Filed: 01/12/2004
• Published: 08/26/2004
• Est. Priority Date: 11/15/2000
• Status: Active Grant

• Current Assignee: Doug Carson & Associates, Inc.
• Original Assignee: Doug Carson & Associates, Inc.
• Inventors: Carson, Douglas M.
• Granted Patent: US 7,568,081 B2
• Time in Patent Office: Days
• US Class Current: 711/112
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• 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 20/00173 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 20/0063 wherein the modification to the logical format mainly concerns management data, e.g., by changing the format of the TOC or the subcode

Abstract

A data storage medium (230, 400) and associated method (500, 520), apparatus (250, 430) and application routine (110, 524) for authenticating the medium as an authentic copy. The medium (such as a prerecorded or recordable optical disc) is formatted so that a predefined relationship is established (502) between physical locations of at least first and second addressable data sectors (220) prior to recording of data to the sectors (506). The predetermined relationship will be present in an authorized copy of the medium (330) but not in an unauthorized duplicate (332), allowing an application routine to grant or deny access (532, 534) to remaining portions of the medium based on the presence or absence of the detected relationship. The predetermined relationship is further used to embed a forensic data payload to serve as a digital fingerprint on the medium.

Claims

1. A method comprising a step of formatting a data storage medium of the type in which data are stored in addressable sectors on a plurality of tracks so as to affirmatively establish a predefined relationship between physical locations of at least a first sector and a second sector prior to recording of data to said at least first and second sectors, the presence of said predefined relationship between the resulting physical locations of the at least first and second sectors serving to identify the medium as an authorized copy.

2. The method of claim 1, wherein the predetermined relationship of the formatting step is further selected to encode a forensic information payload on the medium.

3. The method of claim 1, wherein the data storage medium is characterized as a master copy, and wherein the method further comprises generating a population of replicated copies from the master copy, each replicated copy exhibiting the predefined relationship.

4. The method of claim 1, further comprising a step of subsequently recording data to the at least first and second sectors.

5. The method of claim 4, further comprising a step of subsequently reading back the data recorded to the first and second sectors to identify the presence of the predefined relationship.

6. The method of claim 5, wherein the presence of the predefined relationship is determined during the reading back the data step by measuring a rotational speed of the medium while the first and second sectors are read.

7. The method of claim 5, wherein the presence of the predefined relationship is determined during the reading back the data step by measuring a required access time to move a transducing head from the first sector to the second sector.

8. The method of claim 5, further comprising a step of granting access to remaining sectors on the medium in response to the identification of the presence of the predefined relationship during the subsequently reading back the data step.

9. The method of claim 1, wherein the data storage medium of the formatting step is characterized as a prerecorded medium.

10. The method of claim 1, wherein the data storage medium is characterized as a recordable medium so that the formatting step comprises generating a frequency modulated pre-groove on the medium which predetermines the locations of the sectors to be written to replicated copies of the medium.

11. The method of claim 1, wherein the data storage medium of the formatting step is characterized as an optical disc.

12. A data storage medium formatted in accordance with the method of claim 1.

13. A method comprising steps of:

predetermining desired physical locations of a plurality of sectors on a data storage medium to affirmatively establish a predetermined relationship between at least a first selected sector and a second selected sector, wherein the predetermined relationship is selected so that a presence of said predetermined relationship in a copy subsequently formed from the data storage medium indicates the copy is authorized, and wherein an absence of said predetermined relationship the copy indicates the copy is an unauthorized duplicate; and

subsequently modulating a writing signal to locate said plurality of sectors on the data storage medium in the predetermined desired physical locations.

14. The method of claim 13, wherein the data storage medium is characterized as a prerecorded medium so that the subsequently modulating step comprises writing data to said plurality of sectors.

15. The method of claim 13, wherein the data storage medium is characterized as a recordable master so that the subsequently modulating step comprises generating a frequency modulated pre-groove on the medium to establish the locations of the plurality of sectors on a replicated recordable medium formed from the recordable master.

16. The method of claim 13, further comprising a step of forming a population of replicated copies from the data storage medium.

17. The method of claim 16, further comprising a step of copying the sectors from a selected one of the replicated copies to another medium to form a duplicate copy, wherein the duplicate copy has a relationship between the resulting physical locations of the first and second sectors that is different from the predetermined relationship on the selected one of the replicated copies.

18. The method of claim 13, wherein the predetermining step comprises constructing a lookup table which specifies a rotational speed of the data storage medium for each revolution of the data storage medium during the subsequently modulating step, said lookup table selected so that a predetermined number of channel bits are recorded to the data storage medium over each said revolution.

19. The method of claim 13, wherein the data storage medium is characterized as an optical disc.

20. A system for formatting a data storage medium, comprising:

a motor configured to rotate the medium in response to a motor speed rotation signal;

a write assembly which selectively writes data to the medium during rotation of said medium in response to a write signal; and

first means for generating at least a selected one of the motor speed rotation signal and the write signal to write data to the medium in relation to a pre-generated profile, said profile establishing a predetermined relationship between at least selected sectors of data on the medium prior to the writing of the data to authenticate a subsequently generated copy of the medium as constituting an authorized copy.

21. The system of claim 20, wherein the first means comprises:

a master clock which generates a master clock signal at a first frequency;

a clock divider circuit which outputs a write clock signal in response to the master clock signal, the write clock signal establishing timing of transitions in the write signal; and

a programmable generator circuit which outputs the motor speed rotation signal in response to the master clock signal and the pre-generated profile.

22. The system of claim 21, wherein the first means further comprises a lookup table which outputs values to the programmable generator circuit in relation to the pre-generated profile to adjust the rotational speed of the motor so that an exact, predetermined number of channel bits are written to the medium over each revolution of the medium.

23. The system of claim 20, wherein the first means comprises:

a master clock which generates a master clock signal at a first frequency;

a programmable generator circuit responsive to the master clock signal which outputs a write clock signal to establish timing of transitions in the write signal; and

a lookup table responsive to a once-per-revolution signal from the motor which outputs values to the programmable generator circuit in relation to the pre-generated profile to adjust frequency of the write clock signal so that an exact, predetermined number of channel bits are written to the medium over each revolution of the medium.

24. The system of claim 20, wherein the first means further configures the predetermined relationship to embed a forensic data payload on the medium.

25. The system of claim 20, wherein the data storage medium is characterized as a prerecorded medium.

26. The system of claim 20, wherein the data storage medium is characterized as a recordable medium so that the write signal generates a frequency modulated pre-groove on the medium which predetermines the locations of the sectors to be written to replicated copies of the medium.

27. The system of claim 20, wherein the data storage medium of the formatting step is characterized as an optical disc.

28. A data storage medium formatted by the system of claim 20.

29. A data storage medium comprising a plurality of addressable data sectors formed on a plurality of tracks, the sectors located in preselected physical locations in accordance with a profile generated prior to recording of the sectors, the profile establishing a predetermined relationship between the physical locations of at least selected sectors to identify the data storage medium as an authorized copy.

30. The data storage medium of claim 29, further chararcterized as a prerecorded medium formed as a replicated copy from a mastering process.

31. The data storage medium of claim 29, further characterized as a recordable medium having pre-groove information recorded to the medium in relation to the profile so that, when data are subsequently written to the medium, the sectors are located in relation to the pre-groove information.

32. The data storage medium of claim 29, wherein the data storage medium is characterized as an optical disc.

33. The data storage medium of claim 32, wherein the optical disc is characterized as a compact disc (CD).

34. The data storage medium of claim 32, wherein the optical disc is characterized as a digital versatile disc (DVD).

35. The data storage medium of claim 32, wherein the optical disc is characterized as a pre-recorded optical disc.

36. The data storage medium of claim 32, wherein the optical disc is characterized as a recordable optical disc to which data can be subsequently recorded.

37. An application routine executed in a processor environment to read data from a data storage medium, the medium formatted by predetermining desired physical locations of a plurality of sectors the medium to establish a predetermined relationship between at least a first selected sector and a second selected sector prior to recording of data to the medium to locate said sectors, and by subsequently modulating a writing signal to locate said sectors on the data storage medium in the predetermined desired physical locations, wherein the application routine is configured to measure an access parameter relating to a sequential access of the at least first and second sectors, grant access to remaining sectors on the medium when the measured access parameter indicates the predetermined relationship is present on the medium, the presence of the predetermined relationship indicating that the medium is an authorized copy, and to deny access to remaining sectors on the medium when the measured access parameter indicates the predetermined relationship is not present on the medium, the absence of the predetermined relationship indicating that the medium is an unauthorized duplicate.

38. The application routine of claim 37, wherein the access parameter measured by the application routine comprises a speed of a motor used to rotate the medium, said speed measured as each of the at least first and second sectors are accessed.

39. The application routine of claim 37, wherein the access parameter measured by the application routine comprises an elapsed access time required to move a data transducing head from the at least first sector to the at least second sector.

40. The application routine of claim 37, wherein the application routine further decodes a forensic data payload from the predetermined relationship.