Recording/reproducing apparatus, data moving method, and data deletion method

• US 20020150245A1
• Filed: 04/03/2002
• Published: 10/17/2002
• Est. Priority Date: 04/11/2001
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ishihara, Hideshi, Sugimoto, Hiroshi, Nagai, Takahiro, Ide, Hirofumi
• Granted Patent: US 7,298,844 B2
• Time in Patent Office: Days
• US Class Current: 380/201
• 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 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00478 wherein contents are decrypted and re-encrypted with a different key when being copied from/to a record carrier
• CPC Class Codes: G11B 20/00528 wherein each title is encrypted with a separate encryption key for each title, e.g. title key for movie, song or data file
• CPC Class Codes: G11B 20/00659 involving a control step which is implemented as an executable file stored on the record carrier
• CPC Class Codes: G11B 20/00666 involving a step of erasing or nullifying data, e.g. data being overwritten with a random string
• CPC Class Codes: G11B 20/00673 wherein the erased or nullified data include a cryptographic key
• CPC Class Codes: G11B 20/00753 wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags

Abstract

A recording/reproducing apparatus includes: a first storage section for storing data structure information which includes encrypted data; a special information holding section for holding special information associated with the data structure information; and a controller for controlling the first storage section and the special information holding section. The data structure information is associated with the special information such that the special information is updated in response to an update of the data structure information, or such that the data structure information is updated in response to an update of the special information. The controller controls movement of the encrypted data from the first storage section to a second storage section, and the controller updates the special information such that a mismatch occurs between the special information obtained before the movement of the encrypted data and the special information obtained after the movement of the encrypted data.

Claims

1. A recording/reproducing apparatus, comprising:

a first storage section for storing data structure information which includes encrypted data;

a special information holding section for holding special information associated with the data structure information; and

a controller for controlling the first storage section and the special information holding section,

wherein the data structure information and the special information are associated with each other such that the special information is updated in response to an update of the data structure information, or such that the data structure information is updated in response to an update of the special information,

the controller controls movement of the encrypted data from the first storage section to a second storage section, and

the controller updates the special information held in the special information holding section such that a mismatch occurs between the special information obtained before the movement of the encrypted data from the first storage section to the second storage section and the special information obtained after the movement of the encrypted data from the first storage section to the second storage section.

2. A recording/reproducing apparatus according to claim 1, wherein the second storage section is provided inside of the recording/reproducing apparatus.

3. A recording/reproducing apparatus according to claim 1, wherein the second storage section is provided outside of the recording/reproducing apparatus.

4. A recording/reproducing apparatus according to claim 1, wherein the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

wherein the special information is the system key,

every time the encrypted data is moved from the first storage section to the second storage section, the controller deletes the moved data from the object region, updates the management information; and

deletes from the encryption region the encrypted title key which is used for decrypting the moved data, and

the controller updates the system key and encrypts the title key using the updated system key.

5. A recording/reproducing apparatus according to claim 1, wherein the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key and the management information which are encrypted using a system key,

wherein the special information is the system key,

the controller controls a movement of a predetermined amount of content included in the encrypted data from the first storage section to the second storage sections

the controller updates the system key every time the predetermined amount of content is moved from the first storage section to the second storage section,

every time the predetermined amount of content is moved from the first storage section to the second storage section, the controller deletes the moved predetermined amount of content from the object region, updates the management information, and encrypts the title key and the updated management information using the updated system key, and

when the amount of moved contents becomes equal to the predetermined unit data amount, the controller deletes from the encryption region the encrypted title key which is used for decrypting the data.

6. A recording/reproducing apparatus according to claim 5, wherein, at the start-up of the recording/reproducing apparatus, the controller decrypts the management information using the system key, and overwrites the decrypted management information in the management region.

7. A recording/reproducing apparatus according to claim 1, wherein the data structure information includes:

an object region for storing a content which is a part of the encrypted data and which is encrypted using a title key corresponding to the content; and

a management region for storing management information of the encrypted content and correspondence information which represents a correspondence between the encrypted content and the title key used for decrypting the encrypted content, the correspondence being established by allocating ID information to the encrypted content,

wherein the special information includes the title key to which the ID information is allocated and which is encrypted using a system key,

the controller controls a movement of the encrypted content from the first storage section to the second storage section,

every time the encrypted content is moved from the first storage section to the second storage section, the controller deletes the moved content from the object region and updates the management information, and

every time the encrypted content is moved from the first storage section to the second storage section, the controller deletes from the special information holding section the encrypted title key which has the same ID information as that allocated to the deleted content, thereby updating the special information held in the special information holding section.

8. A recording/reproducing apparatus according to claim 7, wherein:

the special information further includes the system key; and

the controller updates the system key at a predetermined time interval, and encrypts the title key using the updated system key, thereby updating the special information held in the special information holding section.

9. A recording/reproducing apparatus according to claim 1, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key, the special information includes;

a first check code which is calculated from the management information; and

a second check code which is calculated from the encrypted title key,

the controller controls a movement of a predetermined amount of content included in the encrypted data from the first storage section to the second storage section,

every time the predetermined amount of content is moved from the first storage section to the second storage section, the controller deletes from the object region the moved predetermined amount of content, thereby updating the management information,

every time the predetermined amount of content is deleted from the first storage section, the controller updates the first check code held in the special information holding section by means of a calculation based on the updated management information,

when the amount of moved contents becomes equal to the predetermined unit data amount, the controller deletes from the encryption region the encrypted title key which is used for decrypting the data, and

every time the data is deleted, the controller updates the second check code held in the special information holding section by means of a calculation based on the encrypted title key.

10. A recording/reproducing apparatus according to claim 9, wherein:

the special information further includes the system key,

the controller updates the system key every time the predetermined amount of content is moved from the first storage section to the second storage section, and

the controller encrypts the title key using the updated system key, thereby updating the encryption region.

11. A recording/reproducing apparatus according to claim 9, wherein the controller determines whether or not a first check code and a second check code, which are calculated at the start-up of the recording/reproducing apparatus from the management information and the encrypted title key, respectively, are identical to the first check code and the second check code held in the special information holding section.

13. A recording/reproducing apparatus according to claim 12, wherein the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

wherein the special information is the system key,

the data is a content which can be stored for a predetermined time period,

every time the content is deleted from the storage section after a predetermined time period has elapsed, the controller updates the management information and the system key, and

the controller deletes from the encryption region the encrypted title key used for decrypting the content, and encrypts the title key using the updated system key.

14. A recording/reproducing apparatus according to claim 12, wherein the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key and management information which are encrypted using a system key,

wherein the special information is the system key,

every time the content is deleted from the storage section after a predetermined time period has elapsed, the controller updates the management information and the system key,

the controller encrypts the title key and the updated management information using the updated system key, and

when the amount of deleted contents becomes equal to the predetermined unit data amount, the controller deletes from the encryption region the encrypted title key which is used for decrypting the data.

15. A recording/reproducing apparatus according to claim 12, wherein the data structure information includes:

an object region for storing a content which is a part of the encrypted data and which is encrypted using a title key corresponding to the content; and

a management region for storing management information of the encrypted content and correspondence information which represents a correspondence between the encrypted content and the title key used for decrypting the encrypted content, the correspondence being established by allocating ID information to the encrypted content,

wherein the special information includes the title key to which the ID information is allocated and which is encrypted using a system key,

every time the encrypted content is deleted from the storage section after a predetermined time period has elapsed, the controller updates the management information, and

every time the encrypted content is deleted from the storage section after a predetermined time period has elapsed, the controller deletes from the special information holding section the encrypted title key which has the same ID information as that allocated to the deleted content, thereby updating the special information held in the special information holding section.

16. A recording/reproducing apparatus according to claim 15, wherein:

the special information further includes the system key, and

the controller updates the system key at every predetermined time, and encrypts the title key using the updated system key, thereby updating the special information held in the special information holding section.

17. A recording/reproducing apparatus/according to claim 12, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

the special information includes;

a first check code which is calculated from the management information; and

a second check code which is calculated from the encrypted title key,

every time the predetermined amount of content is deleted from the storage section after a predetermined time period has elapsed, the controller updates the management information,

every time the management information is updated, the controller updates the first check code held in the special information holding section by means of a calculation based on the updated management information,

when the amount of deleted content becomes equal to the predetermined unit data amount, the controller deletes from the encryption region the encrypted title key which is used for decrypting the data, thereby updating the encryption region, and

the controller updates the second check code held in the special information holding section by means of a calculation based on the encrypted title key.

18. A recording/reproducing apparatus according to claim 12, wherein:

the special information further includes the system key,

every time the predetermined amount of content is deleted from the storage section after a predetermined time period has elapsed, the controller updates the system key, and

every time the system key is updated, the controller encrypts the title key using the updated system key, thereby updating the encryption region.

20. A method according to claim 19, where in the second storage section is provided inside of the recording/reproducing apparatus.

21. A method according to claim 19, where in the second storage section is provided outside of the recording/reproducing apparatus.

22. A method according to claim 19, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

the special information is the system key,

step b) includes steps of;

b1) deleting the roved data from the object region and updating the management information;

b2) deleting from the encryption region the encrypted title key which is used for decrypting the moved data;

b3) updating the system key; and

b4) encrypting the title key using the updated system key.

23. A method according to claim 19, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key and the management information which are encrypted using a system key,

the special information is the system key,

step a) includes a step of moving a predetermined amount of content included in the encrypted data from the first storage section to the second storage section, and

step b) includes steps of;

b1) deleting the moved predetermined amount of content from the object region;

b2) updating the management information;

b3) updating the system key; and

b4) encrypting the title key and the updated management information using the updated system key, the method further includes steps of;

c) repeating steps a) and b) until the amount of the moved content becomes equal to the predetermined unit data amount; and

d) when the amount of moved content becomes equal to the predetermined unit data amount, deleting from the encryption region the encrypted title key which is used for decrypting the data.

24. A method according to claim 23, further comprising steps of:

e) acquiring the system key from the special information holding section;

f ) decrypting the management information stored in the encryption region using the system key; and

g) overwriting the decrypted management information in the management region.

25. A method according to claim 19, wherein

the data structure information includes:

an object region for storing a content which is a part of the encrypted data and which is encrypted using a title key corresponding to the content; and

a management region for storing management information of the encrypted content and correspondence information which represents a correspondence between the encrypted content and the title key used for decrypting the encrypted content, the correspondence being established by allocating ID information to the encrypted content,

the special information includes the title key to which the ID information is allocated and which is encrypted using a system key,

step a) includes a step of moving the encrypted content from the first storage section to the second storage section, and

step b) includes steps of;

b1) deleting the moved content from the object region;

b2) updating the management information; and

b3) deleting the encrypted title key which has the same ID information as that allocated to the content deleted at step b1).

26. A method according to claim 25, wherein:

the special information further includes the system key; and

step b) further includes a step of updating the system key at every predetermined time and encrypting the title key using the updated system key.

27. A method according to claim 19, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

the special information includes;

a first check code which is calculated from the management information; and

a second check code which is calculated from the encrypted title key,

step a) includes a step of moving a predetermined amount of content included in the encrypted data from the first storage section to the second storage section,

step b) includes steps of;

b1) deleting the moved predetermined amount of content from the object region

b2) updating the management information; and

b3) updating the first check code by means of a calculation based on the updated management information, and

the method further includes steps of;

c) repeating steps a) and b) until the amount of the moved content becomes equal to the predetermined unit data amount;

d) when the amount of moved content becomes equal to the predetermined unit data amount, deleting from the encryption region the encrypted title key which is used for decrypting the data; and

e) updating the second check code by means of a calculation based on the encrypted title key.

28. A method according to claim 27, wherein:

the special information further includes the system key; and

step b)further includes a step of updating the system key and encrypting the title key using the updated system key.

29. A method according to claim 27, further comprising steps of

f) calculating the first check code from the management information;

g) determining whether or not the first check code obtained at step f) is identical to the first check code held in the special information holding section;

h) if the determination result of step g) indicates “

not identical”

, restricting the controller in controlling the first storage section, but if the determination result of step g) indicates “

identical”

, calculating the second check code from the encrypted title key;

i) determining whether or not the second check code obtained at step h) is identical to the second check code held in the special information holding section; and

j) if the determination result of step i) indicates “

not identical”

, restricting the controller in controlling the first storage section, but if the determination result of step i) indicates “

identical”

, allowing the controller to control the first storage section.

33. A method according to claim 24, wherein

the data structure information includes:

an object region for storing a content which is a part of the encrypted data and which is encrypted using a title key corresponding to the content; and

a management region for storing management information of the encrypted content and correspondence information which represents a correspondence between the encrypted content and the title key used for decrypting the encrypted content, the correspondence being established by allocating ID information to the encrypted content,

the special information includes the title key to which the ID information is allocated and which is encrypted using a system key,

step b) includes steps of;

b1) updating the management information; and

b2) deleting the encrypted title key which has the same ID information as that allocated to the deleted content.

34. A method according to claim 33, wherein:

the special information further includes the system key; and

step b) further includes a step of updating the system key at every predetermined time and encrypting the title key using the updated system key.

36. A method according to claim 35, wherein:

the special information further includes the system key; and

step b)further includes a step of updating the system key and encrypting the title key using the updated system key.

12. A recording/reproducing apparatus, comprising:

a storage section for storing data structure information which includes encrypted data, the encrypted data including a content which is allowed to be stored for a predetermined time period;

a special information holding section for holding special information associated with the data structure information; and

a controller for controlling the storage section and the special information holding section,

wherein the data structure information and the special information are associated with each other such that the special information is updated in response to an update of the data structure information, or such that the data structure information is updated in response to an update of the special information,

the controller controls deletion of the content from the storage section after a predetermined time period has elapsed, and

the controller updates the special information held in the special information holding section such that a mismatch occurs between the special information obtained before the deletion of the content from the storage section and the special information obtained after the deletion of the content from the storage section.

19. A method for moving data from a recording/reproducing apparatus, the recording/reproducing apparatus including:

a first storage section for storing data structure information which includes encrypted data;

a special information holding section for holding special information associated with the data structure information; and

a controller for controlling the first storage section and the special information holding section,

wherein the data structure information and the special information are associated with each other such that the special information is updated in response to an update of the data structure information, or such that the data structure information is updated in response to an update of the special information,

the method comprising steps of;

a) moving the encrypted data from the first storage section to a second storage section; and

b) updating the special information held in the special information holding section every time step a) is completed such that a mismatch occurs between the special information obtained before step a) and the updated special information.

30. A method for deleting data from a recording/reproducing apparatus, the recording/reproducing apparatus including:

a storage section for storing data structure information which includes encrypted data, the encrypted data including a content which is allowed to be stored for a predetermined time period;

a special information holding section for holding special information associated with the data structure information; and

a controller for controlling the storage section and the special information holding section,

wherein the data structure information and the special information are associated with each other such that the special information is updated in response to an update of the data structure information, or such that the data structure information is updated in response to an update of the special information,

the method comprising steps of;

a) after a predetermined time period has elapsed, deleting the content from the storage section; and

b) updating the special information held in the special information holding section every time step a) is completed such that a mismatch occurs between the special information obtained before step a) and the updated special information.

31. A method according to claim 30, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

the special information is the system key,

the data is a content which can be stored for a predetermined time period,

step b) includes steps of;

b1) updating the management information;

b2) updating the system key;

b3) deleting from the encryption region the encrypted title key which is used for decrypting the content; and

b4) encrypting the title key again using the updated system key.

32. A method according to claim 30, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key and the management information which are encrypted using a system key,

the special information is the system key,

step b) includes steps of;

b1) updating the management information;

b2) updating the system key; and

b3) encrypting the title key and the updated management information using the updated system key, the method further includes,

c) repeating steps a) and b) until the amount of the deleted content becomes equal to the predetermined unit data amount; and

d) when the amount of deleted content becomes equal to the predetermined unit data amount, deleting from the encryption region the encrypted title key which is used for decrypting the data.

35. A method according to claim 30, wherein

the data structure information includes:

an object region for storing data which is encrypted using a title key corresponding to a predetermined unit amount of data;

a management region for storing management information of the encrypted data; and

an encryption region for storing the title key which is encrypted using a system key,

the special information includes;

a first check code which is calculated from the management information; and

a second check code which is calculated from the encrypted title key,

step b) includes steps of;

b1) updating the management information; and

b2) updating the first check code by means of a calculation based on the updated management information, and

the method further includes steps of;

c) repeating steps a) and b) until the amount of the deleted content becomes equal to the predetermined unit data amount;

d) when the amount of deleted content becomes equal to the predetermined unit data amount, deleting from the encryption region the encrypted title key which is used for decrypting the data; and

e) updating the second check code by means of a calculation based on the encrypted title key.