Data alteration checking apparatus and method and recording medium

• US 6,934,847 B2
• Filed: 08/31/2001
• Issued: 08/23/2005
• Est. Priority Date: 09/01/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ishizaka, Toshihiro
• Primary Examiner(s): Zand, Kambiz
• Application Number:
  US09/944,749
• Publication Number:
  US 20020064281A1
• Time in Patent Office: 1,453 Days
• Field of Search: 713/167, 713/181, 713/193, 713/168, 713/180, 714/746, 380/28, 380/201, 380/228, 380/37, 360/60, 369/84, 369/85, 705/57, 705/58
• US Class Current: 713/181
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• 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: G06F 2221/2145 Inheriting rights or properties, e.g., propagation of permissions or restrictions within a hierarchy
• 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 20/12 Formatting, e.g. arrangement of data block or words on the record carriers within interface between computers and data recorders G06F3/06
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11B 2220/2537 Optical discs
• CPC Class Codes: G11B 2220/2562 DVDs [digital versatile discs]; Digital video discs; MMCDs; HDCDs

Abstract

MAC values formed with respect to each file belonging to a directory 122A and ICVs (D-ICVc) formed on the basis of the MAC values of all files belonging to the directory 122A are stored into a sequence page 121A. Sequence pages 121A, 121B, . . . formed respectively with respect to all of directories 122A, 122B, . . . on a disk and the ICVs formed on the basis of the D-ICVs stored in all of the sequence pages 121A, 121B, . . . are stored into a sequence block 114. Since the MAC values are closed and managed every directory by the sequence pages 121A, 121B, . . . , a data alteration check can be executed every directory. An alteration check of data recorded on a recording medium can be efficiently performed.

Claims

1. A data alteration checking apparatus for discriminating whether data recorded on a recording medium has been altered or not, comprising:

reading means for respectively reading out a data block and a file from said recording medium on which with respect to one or each of a plurality of files belonging to a directory serving as an upper concept in which one or a plurality of files are bound, the data block including one or a plurality of list-type data structures each including a plurality of first arithmetic operation values which were arithmetically operated every said file on the basis of attribute information of the file by a predetermined arithmetic operating method which uses a unidirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from a MAC value has been recorded into an area that is not accessed by a file system on said recording medium and each of said first arithmetic operation values has been written into the corresponding file; and

comparing means for comparing a second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method on the basis of the attribute information of said file read out by said reading means with said first arithmetic operation value which corresponds to said file and is included in said list-type data structure corresponding to said directory to which said file read out by said reading means belongs in said data block read out by said reading means,

wherein on the basis of a result of the comparison by said comparing means, when said first and second arithmetic operation values do not coincide, it is determined that said file has been altered.

2. The apparatus according to claim 1, wherein

a third arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method by using said first arithmetic operation values of all of said files belonging to said directory with respect to each of said directories included in said list-type data structure is further included in said list-type data structure recorded on said recording medium, and

a fourth arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method by using said third arithmetic operation values of all of said list-type data structure included in said data block is included in said data block recorded on said recording medium.

3. The apparatus according to claim 2, wherein

when said file is read out from said recording medium by said reading means, said third arithmetic operation value of said list-type data structure which corresponds to said directory serving as a target and is included in said data block read out by said reading means is compared with a fifth arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method by using said first arithmetic operation values of all of said files belonging to said directory serving as said target, and

as a result of said comparison, if said third and fifth arithmetic operation values do not coincide, it is determined that said directory has been altered.

4. The apparatus according to claim 1, wherein said files are bound in said directory in accordance with a kind of said file.

5. The apparatus according to claim 4, wherein when the kind of said file indicates the file which does not need the data alteration check, said data alteration check for said directory to which the kind of said file corresponds is not performed.

6. The apparatus according to claim 4, wherein the kind of said file is based on contents of the data which is stored into said file.

7. The apparatus according to claim 4, wherein the kind of said file is based on the presence or absence of a protection to said file.

8. The apparatus according to claim 1, further comprising recording means for recording the data onto the recording medium, and

wherein said data block has a field in which the number of updating times of said data block or a value showing that said data block is invalid is stored, and

said recording means is constructed in a manner such that said data block is written twice into the area which is not accessed by said file system, when said data block is rewritten, a value of said field of one of said twice-written data blocks is set to the value showing that said data block is invalid, said one data block is rewritten, when said rewriting is finished, the value of said field of said one data block is set to a value indicative of the number of updating times of said one data block, a value of said field of the other one of said twice-written data blocks is set to the value showing that said data block is invalid, said other data block is rewritten, and when said rewriting is finished, the value of said field of said other data block is set to a value indicative of the number of updating times of said other data block.

9. The apparatus according to claim 1, wherein said first arithmetic operation values are arranged in the searching order of a tree structure in which the corresponding file is constructed by the file system and are stored into said list-type data structure.

10. A data alteration checking method of discriminating whether data recorded on a recording medium has been altered or not, comprising:

a reading step of respectively reading out a data block and a file from said recording medium on which with respect to one or each of a plurality of files belonging to a directory serving as an upper concept in which one or a plurality of files are bound, the data block including one or a plurality of list-type data structures each including a plurality of first arithmetic operation values which were arithmetically operated every file on the basis of attribute information of said file by a predetermined arithmetic operating method which uses a undirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from MAC value has been recorded into an area that is not accessed by a file system on said recording medium and each of said first arithmetic operation values has been written into the corresponding file; and

a comparing step of comparing a second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method on the basis of said attribute information of said file read out by said reading step with said first arithmetic operation value which corresponds to said file and is included in said list-type data structure corresponding to said directory to which said file read out by said reading step belongs in said data block read out by said reading step,

wherein on the basis of a result of the comparison by said comparing step, when said first and second arithmetic operation values do not coincide, it is determined that said file has been altered.

11. A recording medium on which data is recorded by a file structure having a directory serving as an upper concept in which one or a plurality of files are bound, wherein with respect to one or each of said plurality of files said files are bound, a data block including one or a plurality of list-type data structures each including a plurality of first arithmetic operation values which were arithmetically operated every file on the basis of attribute information of said file by a predetermined arithmetic operating method which uses a unidirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from a MAC value is recorded into an area that is not accessed by a file system and each of said first arithmetic operation values is written into the corresponding file, said data block being written twice into the area which is not accessed by said file system and having a field in which the number of updating times of said data block or a value showing that said data block is invalid is stored.

12. A medium according to claim 11, wherein

a second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method by using said first arithmetic operation values of all of said files belonging to said directory with respect to each of said directories included in said list-type data structure is further included in said list-type data structure, and

a third arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method by using said second arithmetic operation values of all of said list-type data structure included in said data block is included in said data block.

13. The medium according to claim 11, wherein said files are bound in said directory in accordance with a kind of said file.

14. The medium according to claim 13, wherein the kind of said file is based on contents of the data which is stored into said file.

15. The medium according to claim 13, wherein the kind of said file is based on the presence or absence of a protection to said file.

16. The medium according to claim 11, wherein when said data block is rewritten, a value of said field of one of said twice-written data blocks is set to the value showing that said data block is invalid, said one data block is rewritten, when said rewriting is finished, the value of said field of said one data block is set to a value indicative of the number of updating times of said one data block, a value of said field of the other one of said twice-written data blocks is set to the value showing that said data block is invalid, said other data block is rewritten, and when said rewriting is finished, the value of said field of said other data block is set to a value indicative of the number of updating times of said other data block.

17. The medium according to claim 11, wherein a size of said data block is set to a variable length in accordance with the number of said directories existing on the recording medium on which said data block is recorded.

18. The medium according to claim 11, wherein said list-type data structure is set to a variable length in accordance with the number of said files belonging to said directory to which said list-type data structure corresponds.

19. The medium according to claim 11, wherein said first arithmetic operation values are arranged in the searching order of a tree structure in which the corresponding file is constructed by the file system and are stored into said list-type data structure.

20. A data alteration checking apparatus for discriminating whether data recorded on a recording medium has been altered or not, comprising:

reproducing means for reproducing said recording medium on which unique identification information is fixedly recorded every recording medium, and with respect to one or each of a plurality of files recorded on said recording medium, a first arithmetic operation value which was arithmetically operated on the basis of attribute information of said file and said identification information by a predetermined arithmetic operating method which uses a unidirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from a MAC value has been stored, said first arithmetic operation value having been recorded in an area which is not accessed by a file system of said recording medium; and

comparing means for comparing said first arithmetic operation value stored in said file reproduced by said reproducing means with a second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method on the basis of said attribute information of said file reproduced by said reproducing means and said identification information,

wherein on the basis of a result of the comparison by said comparing means, when said first and second arithmetic operation values do not coincide, it is determined that said file is illegal.

21. The apparatus according to claim 20, wherein,

a list-type data structure is recorded on said recording medium in which said first arithmetic operation values of every one or a plurality of said files recorded on said recording medium have been stored is recorded, and

when said file recorded on said recording medium is reproduced by said reproducing means, said first arithmetic operation value stored in said list-type data structure is compared with said second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method on the basis of said attribute information of said file reproduced by said reproducing means and said identification information, and when said first and second arithmetic operation values do not coincide, it is determined that said file is illegal.

22. The apparatus according to claim 20, wherein said identification information is ID information which was uniquely determined every said recording medium.

23. The apparatus according to claim 20, wherein said identification information is information indicative of physical defect information of said recording medium.

24. The apparatus according to claim 20, wherein said identification information comprises both of ID information which was uniquely determined every said recording medium and physical defect information of said recording medium.

25. The apparatus according to claim 20, wherein said attribute information is copyright information of said file.

26. The apparatus according to claim 20, wherein said attribute information is present state value information of said file.

27. A data alteration checking method of discriminating whether data recorded on a recording medium has been altered or not, comprising:

a reproducing step of reproducing said recording medium on which unique identification information is fixedly recorded every recording medium, and with respect to one or each of a plurality of files recorded on said recording medium, a first arithmetic operation value which was arithmetically operated on the basis of attribute information of said file and said identification information by a predetermined arithmetic operating method which uses a undirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from a MAC value has been stored, said first arithmetic operation value having been recorded in an area which is not accessed by a file system of said recording medium; and

a comparing step of comparing said first arithmetic operation value stored in said file reproduced by said reproducing step with a second arithmetic operation value which was arithmetically operated by said predetermined arithmetic operating method on the basis of said attribute information of said file reproduced by said reproducing step and said identification information,

wherein on the basis of a result of the comparison by said comparing step, when said first and second arithmetic operation values do not coincide, it is determined that said file is illegal.

28. A recording medium onto/from which data can be recorded and/or reproduced, wherein

unique identification information is fixedly recorded every medium, and one or a plurality of said files in each of which a first arithmetic operation value which was arithmetically operated on the basis of attribute information of said file and said identification information by a predetermined arithmetic operating method which uses a undirectional function and an original value cannot be obtained by performing a reverse arithmetic operation from a MAC has been stored are recorded;

and

wherein a list-type data structure in which said first arithmetic operation value of one or each of a plurality of said recorded files has been stored is recorded into an area which is not accessed by a file system; and

wherein a list-type data structure in which said first arithmetic operation value of one or each of a plurality of said recorded files has been stored is recorded into an area which is not accessed by a file system, said list-type data structure including a data block having a field in which the number of updating times of said data block or a value showing that said data block is invalid is stored.

29. The medium according to claim 28, wherein said identification information is ID information which was uniquely determined every said medium.

30. The medium according to claim 28, wherein said identification information is information indicative of physical defect information of said medium.

31. The medium according to claim 28, wherein said identification information comprises both of ID information which was uniquely determined every said medium and physical defect information of said medium.

32. The medium according to claim 28, wherein said attribute information is copyright information of said file.

33. The medium according to claim 28, wherein said attribute information is present state value information of said file.