Content usage authority management system and management method

• US 20040039911A1
• Filed: 09/08/2003
• Published: 02/26/2004
• Est. Priority Date: 09/11/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ishibashi, Yoshihito, Abe, Hiroshi, Enari, Masahiko, Yoshino, Kenji, Oka, Makoto, Shimada, Noboru
• Granted Patent: US 7,496,756 B2
• Time in Patent Office: Days
• US Class Current: 713/175
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions

Abstract

To implement a system in which content usage conditions can be upgraded without the need for a service provider to control content-usage rights of a user. In the system in which encrypted content is distributed and is allowed to be utilized only by authorized users, the service provider receives a content usage-right certificate from the user, and on the condition that it is determined that data is not tampered with by verifying a digital signature of an issuing entity of the content usage-right certificate, the service provider obtains user information and content purchase information of the user from the content usage-right certificate, and performs upgrade processing by, for example, changing the usage conditions. It is thus possible to change the content usage conditions without the need for the service provider to possess usage control data.

Claims

1. A content usage-right management system comprising:

a user device which utilizes content; and

a service provider which distributes a content usage-right certificate in which content-usage condition information is stored to said user device, wherein;

said user device is configured to utilize the content according to the content-usage condition information stored in the content usage-right certificate received from said service provider, and to make a request to change the content-usage condition information stored in the content usage-right certificate by sending the content usage-right certificate to said service provider; and

said service provider is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

2. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said user device is configured to obtain the content key by decrypting the encrypted content key on the condition that the content is to be utilized according to the content-usage condition information stored in the content usage-right certificate received from said service provider.

3. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said user device is configured to determine whether the content is to be utilized according to the content-usage condition information stored in the content usage-right certificate received from said service provider, and on the condition that the content is to be utilized according to the content usage conditions, said user device decrypts the encrypted content key stored in the content usage-right certificate based on a key stored in said user device.

4. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said service provider is configured to receive the content usage-right certificate sent from said user device, and to determine whether the content is to be utilized according to the content-usage condition information stored in the received content usage-right certificate, and on the condition that the content is to be utilized according to the content usage conditions, said service provider decrypts the encrypted content key stored in the content usage-right certificate based on a unique key of said service provider.

5. A content usage-right management system according to claim 1, wherein:

the content-usage condition information stored in the content usage-right certificate is one of three modes;

content usage-period restricted information, content usage-number restricted information, and content full-purchase without imposing any usage restriction;

the request to change the content-usage condition information from said user device includes at least one of a change in a content usage-period restriction, a change in a content usage-number restriction, and a change among the three modes;

a usage period restriction, a usage number restriction, and content full-purchase; and

said service provider is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by performing at least one of a change in the content usage-period restriction, a change in the content usage-number restriction, or a change among the three modes;

the usage-period restriction, the usage-number restriction, and the content full-purchase for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

6. A content usage-right management system according to claim 1, wherein:

the content-usage conditions stored in the content usage-right certificate include usage condition information in which on-line usage that requires a determination of usage rights in said service provider or off-line usage that does not require a determination of usage rights in said service provider is set; and

said service provider is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by changing the usage-condition information between on-line usage and off-line usage for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

7. A content usage-right management system according to claim 1, wherein:

a digital signature of an entity that has issued the content usage-right certificate is attached to the content usage-right certificate; and

said service provider is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate when it is determined that data is not tampered with by verifying the digital signature.

8. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate stores therein link information concerning a public key certificate corresponding to the content usage-right certificate; and

said service provider is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the public key certificate obtained by the link information.

9. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate is an attribute certificate issued by an attribute certificate authority; and

an encrypted content key encrypted with a content key used for decrypting content is stored in an attribute information field of the attribute certificate.

10. A content usage-right management system according to claim 1, wherein:

the content usage-right certificate is an attribute certificate issued by an attribute certificate authority; and

the content usage conditions are stored in an attribute information field of the attribute certificate.

11. A content usage-right management system comprising:

a user device which utilizes content; and

a service provider which distributes a content usage-right certificate in which purchased content information is stored to said user device, wherein;

said user device is configured to send the content usage-right certificate to said service provider; and

said service provider is configured to generate, based on the content information stored in the content usage-right certificate received from said user device, a content usage-right certificate corresponding to an item of content belonging to an album which consists of a set of items of content, which belong to the same group of content as the content information stored in the received content usage-right certificate, as an upgraded content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

12. A content usage-right management system according to claim 11, wherein:

a digital signature of an entity that has issued the content usage-right certificate is attached to the content usage-right certificate; and

said service provider is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate when it is determined that data is not tampered with by verifying the digital signature.

13. A content usage-right management system according to claim 11, wherein:

the content usage-right certificate stores therein link information concerning a public key certificate corresponding to the content usage-right certificate; and

said service provider is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the public key certificate obtained by the link information.

14. A content usage-right management method used in a system which comprises a user device which utilizes content, and a service provider which distributes a content usage-right certificate in which content-usage condition information is stored to said user device, wherein:

said user device is configured to make a request to change the content-usage condition information stored in the content usage-right certificate by sending the content usage-right certificate to said service provider; and

said service provider is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

15. A content usage-right management method according to claim 14, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said user device is configured to obtain the content key by decrypting the encrypted content key on the condition that the content is to be utilized according to the content-usage condition information stored in the content usage-right certificate received from said service provider.

16. A content usage-right management method according to claim 14, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said user device is configured to determine whether the content is to be utilized according to the content-usage condition information stored in the content usage-right certificate received from said service provider, and on the condition that the content is to be utilized according to the content usage conditions, said user device decrypts the encrypted content key stored in the content usage-right certificate based on a key stored in said user device.

17. A content usage-right management method according to claim 14, wherein:

the content usage-right certificate stores therein an encrypted content key encrypted with a content key;

Kc used for decrypting encrypted content; and

said service provider receives the content usage-right certificate sent from said user device, and determines whether the content is to be utilized according to the content-usage condition information stored in the received content usage-right certificate, and on the condition that the content is to be utilized according to the content usage conditions, said service provider decrypts the encrypted content key stored in the content usage-right certificate based on a unique key of said service provider.

18. A content usage-right management method according to claim 14, wherein:

the content-usage condition information stored in the content usage-right certificate is one of three modes;

content usage-period restricted information, content usage-number restricted information, and content full-purchase without imposing any usage restriction;

the request to change the content-usage condition information from said user device includes at least one of a change in a content usage-period restriction, a change in a content usage-number restriction, and a change among the three modes;

a usage period restriction, a usage number restriction, and content full-purchase; and

said service provider generates, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by performing at least one of a change in the content usage-period restriction, a change in the content usage-number restriction, or a change among the three modes;

the usage-period restriction, the usage-number restriction, and the content full-purchase for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

19. A content usage-right management method according to claim 14, wherein:

the content-usage conditions stored in the content usage-right certificate include usage condition information in which on-line usage that requires a determination of usage rights in said service provider or off-line usage that does not require a determination of usage rights in said service provider is set; and

said service provider generates, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by changing the usage-condition information between on-line usage and off-line usage for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

20. A content usage-right management method according to claim 14, wherein:

a digital signature of an entity that has issued the content usage-right certificate is attached to the content usage-right certificate; and

said service provider generates an upgraded content usage-right certificate upon receiving the content usage-right certificate when it is determined that data is not tampered with by verifying the digital signature.

21. A content usage-right management method according to claim 14, wherein:

the content usage-right certificate stores therein link information concerning a public key certificate corresponding to the content usage-right certificate; and

said service provider generates an upgraded content usage-right certificate upon receiving the content usage-right certificate on the Condition that the integrity of the content usage-right certificate is determined by verifying the public key certificate obtained by the link information.

22. A content usage-right management method used in a system which comprises a user device which utilizes content, and a service provider which distributes a content usage-right certificate in which purchased content information is stored to said user device, wherein:

said user device sends the content usage-right certificate to said service provider; and

said service provider generates, based on the content information stored in the content usage-right certificate received from said user device, a content usage-right certificate corresponding to an item of content belonging to an album which consists of a set of items of content, which belong to the same group of content as the content information stored in the received content usage-right certificate, as an upgraded content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

23. A content usage-right management method according to claim 22, wherein:

a digital signature of an entity that has issued the content usage-right certificate is attached to the content usage-right certificate; and

said service provider generates an upgraded content usage-right certificate upon receiving the content usage-right certificate when it is determined that data is not tampered with by verifying the digital signature.

24. A content usage-right management method according to claim 22, wherein:

the content usage-right certificate stores therein link information concerning a public key certificate corresponding to the content usage-right certificate; and

said service provider generates an upgraded content usage-right certificate upon receiving the content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the public key certificate obtained by the link information.

25. An information processing apparatus used in a system which comprises a user device which utilizes content, and a service provider which distributes a content usage-right certificate in which purchased content information is stored to said user device, said information processing apparatus issuing the content usage-right certificate, wherein said information processing apparatus is configured to receive a request to change content-usage conditions of the issued content-usage condition information from said user device, verify the received content usage-right certificate, and generate an upgraded content usage-right certificate by changing the content-usage condition information recorded in the received content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

26. An information processing apparatus according to claim 25, wherein said information processing apparatus is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by performing at least one of a change in a content usage-period restriction, a change in a content usage-number restriction, or a change among three modes:

the usage-period restriction, the usage-number restriction, and the content full-purchase for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

27. An information processing apparatus according to claim 25, wherein:

the content-usage conditions stored in the content usage-right certificate include usage condition information in which on-line usage that requires a determination of usage rights in said service provider or off-line usage that does not require a determination of usage rights in said service provider is set; and

said information processing apparatus is configured to generate, upon receiving the content usage-right certificate involving the request to change the content-usage condition information from said user device, an upgraded content usage-right certificate by changing the usage-condition information between on-line usage and off-line usage for changing the content-usage condition information recorded in the received content usage-right certificate, and sends the upgraded content usage-right certificate to said user device.

28. An information processing apparatus according to claim 25, wherein:

a digital signature of an entity that has issued the content usage-right certificate is attached to the content usage-right certificate; and

said information processing apparatus is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate when it is determined that data is not tampered with by verifying the digital signature.

29. An information processing apparatus according to claim 25, wherein:

the content usage-right certificate stores therein link information concerning a public key certificate corresponding to the content usage-right certificate; and

said information processing apparatus is configured to generate an upgraded content usage-right certificate upon receiving the content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the public key certificate obtained by the link information.

30. A computer program allowing, in a system which comprises a user device which utilizes content, and a service provider which distributes a content usage-right certificate in which purchased content information is stored to said user device, processing for issuing a content usage-right certificate to be executed on a computer system, said computer program comprising:

a step of receiving a request to change content-usage conditions of the issued content-usage condition information;

a step of verifying the received content usage-right certificate; and

a step of generating an upgraded content usage-right certificate by changing the content-usage condition information recorded in the received content usage-right certificate on the condition that the integrity of the content usage-right certificate is determined by verifying the received content usage-right certificate, and sending the upgraded content usage-right certificate to said user device.