Recording apparatus, medium, method, and related computer program

• US 20030041253A1
• Filed: 07/03/2002
• Published: 02/27/2003
• Est. Priority Date: 07/05/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujimura, Kazuya, Nakamura, Norio, Sato, Mitsuhiro, Matsui, Shinichi, Shimojima, Takashi, Noguchi, Naohiko, Hasegawa, Kiichi
• Granted Patent: US 7,269,741 B2
• Time in Patent Office: Days
• US Class Current: 713/189
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/14 Protection against unauthorised use of memory or access to memory
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 21/77 in smart cards

Abstract

A recording apparatus for an SD memory card that has a plurality of EPUBxxx.KEY files recorded thereon, each file having a plurality of Key&Rule Entry areas, and an SD_EPUB.MMG file being read from the recording medium prior to the writing of data. A bitmap in SD_EPUB.MMG shows for each EPUBxxx.KEY file whether the EPUBxxx.KEY file has at least one Key&Rule Entry area not in use, or whether all the Key&Rule Entry areas are in use. Based on the bitmap in the read SD_EPUB.MMG file, the recording apparatus opens EPUB#u.KEY having an unused Key&Rule Entry area and writes data into the unused Key&Rule Entry area in the file. If all the Key&Rule Entry areas in EPUB#u.KEY become in use as a result of the writing of the data, the recording apparatus updates the bitmap in SD_EPUB.MMG.

Claims

1. A recording apparatus for a recording medium that has a plurality of files recorded thereon, each file having a plurality of entry areas, comprising:

a reading unit operable to read condition information from the recording medium, the condition information showing for each file whether the file is in a first condition in which one or more entry areas are not in use, or in a second condition in which all the entry areas are in use;

a writing unit operable to specify a file in a first condition by referring to the read condition information, and to write data into an unused entry area of the specified file; and

an updating unit operable to update the condition information so as to show the specified file as being in the second condition if all the entry areas in the specified file become in use as a result of the writing of the data by the writing unit.

2. The recording apparatus of claim 1, wherein

the condition information is updated by the updating unit so as to show, when an entry area in a file in the second condition becomes not in use, the file as being in the first condition.

3. The recording apparatus of claim 1, wherein

there are m number of files, m being an integer having a value of 2 or greater,

the condition information is a flag sequence consisting of m number of flags that correspond one-to-one with the m number of files, each flag being set as one of an off-flag showing the corresponding file to be in the first condition, and an on-flag showing the corresponding file to be the second condition,

the file specified by the writing unit corresponds to an off-flag, and

the updating by the updating unit involves changing the off-flag to an on-flag if all the entry areas in the specified file become in use as a result of the writing of the data by the writing unit.

4. The recording apparatus of claim 3, wherein

the off-flag to which the file corresponds is an off-flag nearest a head of the flag sequence.

5. The recording apparatus of claim 3, wherein

the condition information is placed in one of the files having the plurality of entry areas, or in a file that is different to the files having the plurality of entry areas.

6. The recording apparatus of claim 1, further comprising:

a creating unit operable to create a file that is in the first condition if all of the files on the recording medium are shown to be in the second condition when the read condition information is referred to by the writing unit.

7. The recording apparatus of claim 1, wherein

there are n number of entry areas in each file, n being an integer having a value of 2 or greater,

the recording medium has further recorded thereon a flag sequence consisting of n number of flags that correspond one-to-one with the n number of entry areas in a file, each flag being set as one of an off-flag showing the corresponding entry area to be not in use, and an on-flag showing the corresponding entry area to be in use, and

the entry area into which the data is to be written by the writing unit is an entry area corresponding to an off-flag.

8. The recording apparatus of claim 7, wherein

the off-flag to which the entry area corresponds is an off-flag nearest a head of the flag sequence.

9. The recording apparatus of claim 7, wherein

the flag sequence is placed in one of the files having the n number of entry areas, or in a file that is different to the files having the n number of entry areas.

10. The recording apparatus of claim 9, wherein

the flag sequence and the condition information are placed in the file that is different to the files having the n number of entry areas.

11. The recording apparatus of claim 1, wherein

the recording medium is a semiconductor memory card that includes an authentication circuit for authenticating an apparatus to which the semiconductor memory card is connected, and a protected area which is accessed by the apparatus only when the apparatus has been authenticated by the authentication circuit, and

the plurality of files are recorded in the protected area.

12. The recording apparatus of claim 11, wherein

the semiconductor memory card further includes a user data area having recorded therein a plurality of encrypted contents,

the plurality of entry areas in the files recorded in the protected area are allotted one-to-one to the plurality of encrypted contents, and

the data written into the unused entry area of the specified file by the writing unit includes one of a decryption key and rights management information, both of which relate to the encrypted content to which the unused entry area is allotted.

13. The recording apparatus of claim 1, wherein

an area of the recording medium is formed from a plurality of clusters,

the entry areas in the files are each of a constant length, and

the number of entry areas in each file is set such that a size of each file is less than or equal to a size of a cluster.

14. The recording apparatus of claim 13, wherein

the recording medium is a semiconductor memory card requiring that data recorded thereon be erased before the writing of the data by the writing unit, and

the size of a cluster is equal to or a fraction of a size of a minimum erasable area of the semiconductor memory card.

15. A recording medium having recorded thereon:

a plurality of files, each of which has a plurality of entry areas; and

condition information showing for each file whether the file is in a first condition in which one or more entry areas are not in use, or in a second condition in which all the entry areas are in use.

16. The recording medium of claim 15, wherein

there are m number of files, m being an integer having a value of 2 or greater, and

the condition information is a flag sequence consisting of m number of flags that correspond one-to-one with the m number of files, each flag being set as one of an off-flag showing the corresponding file to be in the first condition, and an on-flag showing the corresponding file to be the second condition.

17. The recording medium of claim 15, wherein

there are n number of entry areas in each file, n being an integer having a value of 2 or greater, and

the recording medium has further recorded thereon a flag sequence consisting of n number of flags that correspond one-to-one with the n number of entry areas in a file, each flag being set as one of an off-flag showing the corresponding entry area to be not in use, and an on-flag showing the corresponding entry area to be in use.

18. The recording medium of claim 15, wherein

the recording medium is a semiconductor memory card that includes an authentication circuit for authenticating an apparatus to which the semiconductor memory card is connected, and a protected area which is accessed by the apparatus only when the apparatus has been authenticated by the authentication circuit, and

the plurality of files are recorded in the protected area.

19. The recording medium of claim 18, wherein

the semiconductor memory card further includes a user data area having recorded therein a plurality of encrypted contents,

the plurality of entry areas in the files recorded in the protected area are allotted one-to-one to the plurality of encrypted contents, and

the data written into the unused entry area of the specified file by the writing unit includes one of a decryption key and rights management information, both of which relate to the encrypted content to which the unused entry area is allotted.

20. The recording medium of claim 15, wherein

an area of the recording medium is formed from a plurality of clusters,

the entry areas in the files are each of a constant length, and

the number of entry areas in each file is set such that a size of each file is less than or equal to a size of a cluster.

21. The recording medium of claim 20, wherein

the recording medium is a semiconductor memory card requiring that data recorded thereon be erased before the writing of the data by the writing unit, and

the size of a cluster is equal to or a fraction of a size of a minimum erasable area of the semiconductor memory card.

22. A computer program for having a computer perform a recording process relating to a recording medium that has recorded thereon a plurality of files, each of which has a plurality of entry areas, comprising:

a reading step of reading condition information from the recording medium, the condition information showing for each file whether the file is in a first condition in which one or more entry areas are not in use, or in a second condition in which all the entry areas are in use;

a writing step of specifying a file in a first condition by referring to the read condition information, and writing data into an unused entry area of the specified file; and

an updating step of updating the condition information so as to show the specified file as being in the second condition if all the entry areas in the specified file become in use as a result of the writing of the data in the writing step.

23. The computer program of claim 22, wherein

the condition information is updated in the updating step so as to show, when an entry area in a file in the second condition becomes not in use, the file as being in the first condition.

24. The computer program of claim 22, wherein

there are m number of files, m being an integer having a value of 2 or greater,

the condition information is a flag sequence consisting of m number of flags that correspond one-to-one with the m number of files, each flag being set as one of an off-flag showing the corresponding file to be in the first condition, and an on-flag showing the corresponding file to be the second condition,

the file specified in the writing step corresponds to an off-flag, and

the updating in the updating step involves changing the off-flag to an on-flag if all the entry areas in the specified file become in use as a result of the writing of the data in the writing step.

25. The computer program of claim 24, wherein

the off-flag to which the file corresponds is an off-flag nearest a head of the flag sequence.

26. The computer program of claim 24, wherein

the condition information is placed in one of the files having the plurality of entry areas, or in a file that is different to the files having the plurality of entry areas.

27. The computer program of claim 22, further comprising:

a creating step of creating a file that is in the first condition if all of the files on the recording medium are shown to be in the second condition when the read condition information is referred to in the writing step.

28. The computer program of claim 22, wherein

there are n number of entry areas in each file, n being an integer having a value of 2 or greater,

the recording medium has further recorded thereon a flag sequence consisting of n number of flags that correspond one-to-one with the n number of entry areas in a file, each flag being set as one of an off-flag showing the corresponding entry area to be not in use, and an on-flag showing the corresponding entry area to be in use, and

the entry area into which the data is to be written in the writing step is an entry area corresponding to an off-flag.

29. The computer program of claim 28, wherein

the off-flag to which the entry area corresponds is an off-flag nearest a head of the flag sequence.

30. The computer program of claim 28, wherein

the flag sequence is placed in one of the files having the n number of entry areas, or in a file that is different to the files having the n number of entry areas.

31. The computer program of claim 30, wherein

the flag sequence and the condition information are placed in the file that is different to the files having the n number of entry areas.

32. The computer program of claim 22, wherein

the recording medium is a semiconductor memory card that includes an authentication circuit for authenticating an apparatus to which the semiconductor memory card is connected, and a protected area which is accessed by the apparatus only when the apparatus has been authenticated by the authentication circuit, and

the plurality of files are recorded in the protected area.

33. The computer program of claim 32, wherein

the semiconductor memory card further includes a user data area having recorded therein a plurality of encrypted contents,

the plurality of entry areas in the files recorded in the protected area are allotted one-to-one to the plurality of encrypted contents, and

the data written into the unused entry area of the specified file in the writing step includes one of a decryption key and rights management information, both of which relate to the encrypted content to which the unused entry area is allotted.

34. The computer program of claim 22, wherein

an area of the recording medium is formed from a plurality of clusters,

the entry areas in the files are each of a constant length, and

the number of entry areas in each file is set such that a size of each file is less than or equal to a size of a cluster.

35. The computer program of claim 34, wherein

the recording medium is a semiconductor memory card requiring that data recorded thereon be erased before the writing of the data in the writing step, and

the size of a cluster is equal to or a fraction of a size of a minimum erasable area of the semiconductor memory card.

36. The computer program of claim 22, wherein

the computer program is stored on a computer-readable storage medium.

37. A recording method relating to a recording medium having recorded thereon a plurality of files, each of which has a plurality of entry areas, comprising:

a reading step of reading condition information from the recording medium, the condition information showing for each file whether the file is in a first condition in which one or more entry areas are not in use, or in a second condition in which all the entry areas are in use;

a writing step of specifying a file in a first condition by referring to the read condition information, and writing data into at unused entry area of the specified file; and

an updating step of updating the condition information so as to show the specified file as being in the second condition if all the entry areas in the specified file become in use as a result of the writing of the data in the writing step.