Storage Medium Processing Method, Storage Medium Processing Device, and Program

• US 20070248231A1
• Filed: 06/08/2005
• Published: 10/25/2007
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suu, Hiroshi, Miura, Akira, Kasahara, Akihiro
• Granted Patent: US 7,886,361 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: G06F 12/1416 by checking the object accessibility, e.g. type of access defined by the memory independently of subject rights G06F12/1458 takes precedence
• CPC Class Codes: G06F 21/109 by using specially-adapted hardware at the client
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/0894 Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage

Abstract

Rental business of content data is adequately performed while preventing a improper use of rights or the like by a user. Rental user key data Kuren1-3, and rental content key data Kuren1-3 includes management metadata M1-M3 and M1′-M3′, respectively. The management metadata includes data use termination date/time indicating an expiration date or the like.

Claims

1. A storage medium processing method a using a storage medium and a user terminal,

wherein the storage medium stores medium identifier data, medium unique key data enabled to be generated based on the medium identifier data, encrypted user key data in which user key data is encrypted so that it may be decrypted using the medium unique key data, and encrypted content key data in which content key data is encrypted so that it may be decrypted using the user key data,

the user terminal retains encrypted content data in which content data is encrypted so that it may be decrypted using the content key data, and

the user terminal connected to the storage medium is enabled to access to a license center to obtain various kinds of data,

the method comprising:

an issuance step issuing the content key data and the user key data with management data including data of an expiration date of the content key data or the user key data in order to permit the user to use the content data before a certain expiration date in response to request from the user terminal,

a judgment step judging whether or not the user key data or the content key data may be used continuously referring to the management data; and

deleting/use-precluding step deleting or preclude using of the user key data or the content key data based on the judgment result of the judgment step.

2. The storage medium processing method according to claim 1, wherein the issuance step includes a step of detecting an error of time indicated by a clock in the user terminal, and if the error is less than a predetermined value, an issuance of the content key data and the user key data is permitted.

3. The storage medium processing method according to claim 1 wherein the management data includes latest reproduction date/time data indicating a latest reproduction date/time of the content data,

when the time the reproduction request of the content data was made is before the data of the latest reproduction date/time contradiction information is generated to reject a reproduction of the content data thereafter.

4. The storage medium processing method according to claim 1, wherein the judgment step and the deleting/use-precluding step is performed by the license center while the user terminal accessed the license center.

5. The storage medium processing method according to claim 1, wherein the judgment step and the deleting/use-precluding step is performed regularly by the user terminal.

6. The storage medium processing method according to claim 1, wherein the user key data is issued so as to correspond one-on-one to the content key data.

7. The storage medium processing method according to claim 1, wherein the user key data is issued so as to be shared by the content key data having the same expiration date.

8. The storage medium processing method according to claim 1, wherein the management data includes information on an address of the storage medium where the content key data is stored,

and the judgment step judges the propriety of continuous usage based on information on the consistence/inconsistence of the address information.

9. A storage medium processing device which may be connected to a storage medium which stores medium identifier data medium unique key data enabled to be generated based on the medium identifier data, encrypted user key data in which user key data is encrypted so that it may be decrypted using the medium unique key data and encrypted content key data in which content key data is encrypted so that it may be decrypted using the user key data and performs data processing of the storage medium via a user terminal retaining encrypted content data in which content data is encrypted so that it may be decrypted using the content key data,

the device comprising:

a key issuance unit issuing the content key data and the user key data with management data including data of an expiration date of the content key data or the user key data in order to permit the user to use the content data before a certain expiration date in response to request from the user terminal; and

judgment unit judging whether or not the user key data or the content key data may be used continuously referring to the management data, and conduct an instruction to delete the user key data or the content key data or preclude using of the user key data or the content key data when the continuous usage thereof is judged improper.

10. The storage medium processing device according to claim 9, wherein the key issuance unit detects an error of time indicated by a clock in the user terminal, and if the error is less than a predetermined value, issues the content key data and the user key data.

11. The storage medium processing device according to claim 9, wherein the management metadata includes latest reproduction date/time data indicating a latest reproduction date/time of the content data,

when the time the reproduction request of the content data was made is before the data of the latest reproduction date/time, contradiction information is generated to reject a reproduction of the content data thereafter.

12. The storage medium processing device according to claim 9, wherein the management data includes information on an address of the storage medium where the content key data is stored,

and the judgment unit judges the propriety of continuous usage based on information on the consistence/inconsistence of the address information.

13. A storage medium processing program using a storage medium and a user terminal,

wherein the storage medium stores medium identifier data, medium unique key data enabled to be generated based on the medium identifier data, encrypted user key data in which user key data is encrypted so that it may be decrypted using the medium unique key data, and encrypted content key data in which content key data is encrypted so that it may be decrypted using the user key data,

the user terminal retains encrypted content data in which content data is encrypted so that it may be decrypted using the content key data, and

the user terminal connected to the storage medium is enabled to access to a license center to obtain various kinds of data,

the program being configured to perform:

an issuance step issuing the content key data and the user key data with management data including data of an expiration date of the content key data or the user key data in order to permit the user to use the content data before a certain expiration date in response to request from the user terminal;

a judgment step judging whether or not the user key data or the content key data may be used continuously referring to the management data; and

deleting/use-precluding step deleting or preclude using of the user key data or the content key data based on the judgment result of the judgment step.

14. A user terminal configured to be connectable to a storage medium which stores medium identifier data, medium unique key data enabled to be generated based on the medium identifier data, encrypted user key data in which user key data is encrypted so that it may be decrypted using the medium unique key data, and encrypted content key data in which content key data is encrypted so that it may be decrypted using the user key data, configured to be enabled to access to a license center to obtain various kinds of data, and configured to retain encrypted content data in which content data is encrypted so that it may be decrypted using the content key data the user terminal comprising:

a download unit downloading the content key data and the user key data with management data including data of an expiration date of the content key data or the user key data in order to receive permission to use the content data before a certain expiration date,

a processing unit that writes the encrypted user key data and the content key data in the storage medium or reads the encrypted user key data and the content key data from the storage medium, and perform a process of deleting of, or perform a process of precluding use of the user key data or the content key data having the certain expiration date which elapsed.

15. The user terminal according to claim 14, wherein the processing unit updates the management metadata when a certain process is conducted against the content data.

16. The user terminal according to claim 15, wherein the processing unit updates the management metadata when the content data is used.