SECURITY CHIP USED IN A CONTENTS DATA PLAYING DEVICE, UPDATE MANAGEMENT METHOD, AND UPDATE MANAGEMENT PROGRAM

• US 20130227538A1
• Filed: 04/11/2013
• Published: 08/29/2013
• Est. Priority Date: 10/14/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: MARUYAMA, Hidefumi
• Granted Patent: US 9,524,379 B2
• Time in Patent Office: Days
• US Class Current: 717/168
• 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: G06F 21/572 Secure firmware programming, e.g. of basic input output system [BIOS]
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57

Abstract

A security chip is used in a contents data playing device. The security chip includes a storage unit configured to store firmware data including a firmware program, and a firmware update management unit configured to determine whether an update process is to be executed on the firmware data based on a comparison between expiration information set for the firmware data and time information received via a network, in response to a request input to the security chip to acquire a contents key or to decrypt contents data, and to reject the request when the update process is to be executed. The firmware program causes the security chip to function as a contents key acquisition control unit configured to acquire, via the network, the contents key for decrypting the contents data, and a decryption unit configured to decrypt the contents data by using the contents key.

Claims

1. A security chip used in a contents data playing device, the security chip comprising:

a storage unit configured to store firmware data including a firmware program; and

a firmware update management unit configured to determine whether an update process is to be executed on the firmware data based on a comparison between expiration information set for the firmware data and time information received via a network, in response to a request input to the security chip to acquire a contents key or to decrypt contents data, and to reject the request when the update process is to be executed, wherein

the firmware program causes the security chip to function as

a contents key acquisition control unit configured to acquire, via the network, the contents key for decrypting the contents data, and

a decryption unit configured to decrypt the contents data by using the contents key.

2. The security chip according to claim 1, wherein

the contents key acquisition control unit is configured to acquire the time information together with the contents key.

3. The security chip according to claim 2, wherein

the contents key acquisition control unit is configured to acquire the contents key and the time information by encrypted communication.

4. The security chip according to claim 1, wherein

the firmware update management unit is configured to

record, in an update state storage unit, update state information indicating a state of the update process in the update process performed on the firmware data, and

to refer to the update state information in response to the request input to the security chip to acquire the contents key or to decrypt the contents data, and reject the request when the update state information indicates that the update process has not been completed.

5. A method of update management executed by a security chip included in a contents data playing device, the method comprising:

determining whether an update process is to be executed on firmware data stored in a storage unit included in the security chip based on a comparison between expiration information set for the firmware data and time information received via a network, in response to a request input to the security chip to acquire a contents key or to decrypt contents data, and rejecting the request when the update process is to be executed; and

causing, by a firmware program included in the firmware data, the security chip to function as

a contents key acquisition control unit configured to acquire, via the network, the contents key for decrypting the contents data, and

a decryption unit configured to decrypt the contents data by using the contents key.

6. The method according to claim 5, further comprising:

acquiring, by the contents key acquisition control unit, the time information together with the contents key.

7. The method according to claim 6, further comprising:

acquiring, by the contents key acquisition control unit, the contents key and the time information by encrypted communication.

8. The method according to claim 5, further comprising:

recording, by the security chip, update state information in an update state storage unit, the update state information indicating a state of the update process in the update process performed on the firmware data, wherein

the recording includes referring to the update state information in response to the request input to the security chip to acquire the contents key or to decrypt the contents data, and rejecting the request when the update state information indicates that the update process has not been completed.

9. A non-transitory computer-readable recording medium storing a program for executing update management by a security chip included in a contents data playing device, wherein the program causes a computer to execute a process comprising:

determining whether an update process is to be executed on firmware data stored in a storage unit included in the security chip based on a comparison between expiration information set for the firmware data and time information received via a network, in response to a request input to the security chip to acquire a contents key or to decrypt contents data, and rejecting the request when the update process is to be executed; and

causing, by a firmware program included in the firmware data, the security chip to function as

a contents key acquisition control unit configured to acquire, via the network, the contents key for decrypting the contents data, and

a decryption unit configured to decrypt the contents data by using the contents key.

10. The non-transitory computer-readable recording medium according to claim 9, the process further comprising:

acquiring, by the contents key acquisition control unit, the time information together with the contents key.

11. The non-transitory computer-readable recording medium according to claim 10, the process further comprising:

acquiring, by the contents key acquisition control unit, the contents key and the time information by encrypted communication.

12. The non-transitory computer-readable recording medium according to claim 9, the process further comprising:

recording, by the security chip, update state information in an update state storage unit, the update state information indicating a state of the update process in the update process performed on the firmware data, wherein

the recording includes referring to the update state information in response to the request input to the security chip to acquire the contents key or to decrypt the contents data, and rejecting the request when the update state information indicates that the update process has not been completed.