INFORMATION PROCESSING DEVICE, CONTENT PROCESSING SYSTEM, AND COMPUTER READABLE MEDIUM HAVING CONTENT PROCESSING PROGRAM

• US 20100232607A1
• Filed: 03/09/2010
• Published: 09/16/2010
• Est. Priority Date: 03/11/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Isamu, NIMURA, Kazuaki, Nakamura, Yousuke, Honda, Fumio
• Granted Patent: US 8,924,738 B2
• Time in Patent Office: Days
• US Class Current: 380/279
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/4335 Housekeeping operations, e.g. prioritizing content for deletion because of storage space restrictions storage management, e.g. defragmentation G06F3/0604; unloading stored programs G06F9/445; storage management in file systems G06F16/10; buffering arrangements in a network node or in an end terminal in packet networks H04L49/90
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/4882 for displaying messages, e.g. warnings, reminders arrangements for providing short real-time information to substation in data switching networks H04L12/1895
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/163 by receiver means only

Abstract

An information processing device and method include storing encrypted content, storing a key for decrypting the encrypted content stored, decrypting the encrypted content stored using the key, storing a deletion table storing information indicating whether or not the key stored is to be deleted when a transition from an operating state to one of other states is made, the information corresponding to the other states, and checking the information in the deletion table corresponding to the one of the other states and deleting the key when the information indicates that the key is to be deleted.

Claims

1. An information processing device, comprising:

a content storage unit configured to store encrypted content;

a key storage unit configured to store a key for decrypting the encrypted content stored in the content storage unit;

a content processing unit configured to decrypt the encrypted content stored in the content storage unit using the key stored in the key storage unit;

a table storage unit configured to store a deletion table storing information indicating whether the key stored in the key storage unit is to be deleted when a transition from an operating state to one of other states is made, the information corresponding to the other states;

a key deletion unit configured to, when the transition from the operating state to one of the other states is made, check the information in the deletion table corresponding to the one of the other states and delete the key when the information indicates that the key is to be deleted; and

a key acquisition unit configured to acquire the key when the key is not stored in the key storage unit when a transition from the one of the other states to the operating state is made.

2. The information processing device of claim 1, comprising:

a communication unit configured to communicate with a key storage management device which stores and manages the key,

wherein the key acquisition unit acquires the key by causing the communication unit to request the key storage management device to transmit the key and receive the key transmitted from the key storage management device.

3. The information processing device of claim 1, wherein the key acquisition unit determines a presence or an absence of the key by searching in the key storage unit.

4. The information processing device of claim 3, wherein the key acquisition unit checks the information in the deletion table corresponding to a state from which the transition to the operating state is being made and recognizes the absence of the key when the information corresponding to the state indicates that the key is to be deleted.

5. A key storage management device, comprising:

a communication unit configured to communicate with information processing devices which decrypt encrypted content using keys;

a key storage unit configured to store a key for decrypting the encrypted content;

a table storage unit configured to store a key transmission table storing information regarding key transmission permission to the information processing devices, the key transmission permission information corresponding to the information processing devices; and

a key management unit configured to when a key transmission request is received by the communication unit, check information in the key transmission table corresponding to an information processing device from which the key transmission request has been received and, when key transmission to the information processing device is permitted, cause the communication unit to transmit the key to the information processing device.

6. A content processing system in which content processing devices configured to decrypt encrypted content using keys and a key storage management device configured to store and manage the keys are connected to each other via a communication network, comprising:

each of the content processing device including;

a content storage unit configured to store encrypted content;

a first key storage unit configured to store a key for decrypting the encrypted content stored in the content storage unit;

a content processing unit configured to decrypt the encrypted content stored in the content storage unit using the key stored in the first key storage unit and process the decrypted content;

a first table storage unit configured to store a deletion table storing information indicating whether the key stored in the first key storage unit is to be deleted when a transition from an operating state to one of other states is made, the information corresponding to the other states;

a key deletion unit configured to, when the transition from the operating state to one of the other states is made, check the information in the deletion table corresponding to the one of the other states and delete the key when the information indicates that the key is to be deleted;

a first communication unit configured to communicate with the key storage management device; and

a key acquisition unit configured to acquire the key when the key is not stored in the first key storage unit when a transition from the one of the other states to the operating state is made, by causing the communication unit to request the key storage management device to transmit the key and receive the key transmitted from the key storage management device,

the key storage management device comprising;

a second communication unit configured to communicate with the content processing devices;

a second key storage unit configured to store a key for decrypting the encrypted content; and

a key management unit configured to, when a key transmission request is received by the second communication unit, cause the second communication unit to transmit the key to a content processing device from which the key transmission request has been received.

7. The content processing system of claim 6,

wherein the key storage management device includes a second table storage unit configured to store a key transmission table storing information regarding key transmission permission to the content processing devices, the key transmission permission information corresponding to the content processing devices and

wherein when a key transmission request is received by the second communication unit, the key management unit checks the information in the key transmission table corresponding to a content processing device from which the transmission request has been received and, when key transmission to the content processing device is permitted, causes the second communication unit to transmit the key.

8. A storage medium storing a content processing program executed in a computer capable of executing programs to cause the computer to operate as a content processing device including:

storing encrypted content;

storing a key for decrypting the encrypted content stored;

decrypting the encrypted content stored using the key;

storing a deletion table storing information indicating whether the key stored is to be deleted when a transition from an operating state to one of other states is made, the information corresponding to the other states;

checking the information in the deletion table corresponding to the one of the other states and deleting the key when the information indicates that the key is to be deleted; and

acquiring the key when the key is not stored when a transition from the one of the other states to the operating state is made.

9. The storage medium storing the content processing program of claim 8,

wherein the computer has a communication unit configured to communicate with a key storage management device which stores and manages the key, and

wherein the key is acquired when determining that the key is not stored when the transition from the one of the other states to the operating state is made, by causing the communication unit to request the key storage management device to transmit the key and receive the key transmitted from the key storage management device.

10. The storage medium storing the content processing program of claim 8, comprising:

determining a presence or an absence of the key by searching in a key storage unit.

11. The storage medium storing the content processing program of claim 8, comprising:

checking the information in the deletion table corresponding to a state from which the transition to the operating state is being made and recognizing the absence of the key when the information corresponding to the state indicates that the key is to be deleted.

12. A storage medium storing a key storage management program executed in a computer having a communication unit and executing programs, the communication unit communicating with content processing devices configured to decrypt encrypted content using keys, the key storage management program causing the computer to operate as a key storage management device comprising:

storing a key for decrypting the encrypted content;

storing a key transmission table storing information regarding key transmission permission to the content processing devices, the key transmission permission information corresponding to the content processing devices; and

checking the information in the key transmission table corresponding to a content processing device from which a key transmission request has been received and, when key transmission to the content processing device is permitted, causing the communication unit to transmit the key to the content processing device.

13. A computer-implemented method, comprising:

determining an operating state of a device; and

deleting a key for decrypting content in association with the device when said determining indicates that the operating state is transitioning from a first predetermined state to a second predetermined state.