Backup system, recording/reproduction device, backup device, backup method, program, and integrated circuit

• US 8,065,498 B2
• Filed: 12/12/2005
• Issued: 11/22/2011
• Est. Priority Date: 01/07/2005
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nakano, Toshihisa, Ito, Yoshikatsu, Tsusaka, Yuko, Ohmori, Motoji, Harada, Shunji, Fujioka, Soichiro
• Primary Examiner(s): Bragdon; Reginald
• Assistant Examiner(s): VO, THANH DUC
• Application Number:
  US11/794,255
• Publication Number:
  US 20080022061A1
• Time in Patent Office: 2,171 Days
• Field of Search: None
• US Class Current: 711/162
• 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 20/00753 wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/0084 wherein the usage restriction can be expressed as a specific time or date
• CPC Class Codes: G11B 27/034 on discs G11B27/036, G11B27/038 take precedence
• CPC Class Codes: H04N 2005/91328 the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• CPC Class Codes: H04N 21/4135 external recorder interface circuits between an apparatus for recording television signals and a television receiver H04N5/775
• CPC Class Codes: H04N 21/4147 PVR [Personal Video Recorder] H04N5/76 takes precedence ; arrangements for broadcast with accumulation-type receivers H04H20/40
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• 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 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/4627 Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/163 by receiver means only

Abstract

A content of Copy Once cannot be copied to an external device or the like, even for the purpose of making a backup. This is inconvenient for the user. However, if copying to another device for the purpose of making a backup is permitted, the content may be copied in an unauthorized manner. The present invention provides the hard disk recorder that transmits the content to the backup device, sets an expiration time in the content stored in the hard disk recorder itself, and deletes the content stored in the hard disk recorder itself after the expiration time expires.

Claims

1. A backup system comprising a backup device and a recording/playback device for recording and playing back a content,

wherein the recording/playback device includes:

a storage unit storing the content and content information in correspondence with each other;

a receiving unit operable to receive a backup instruction to back up the content;

a content transmitting unit operable to, if the receiving unit receives the backup instruction, read the content from the storage unit and transmit the content to the backup device;

a writing unit operable to, if the receiving unit receives the backup instruction, write period information to the content information stored in the storage unit in correspondence with the content, the period information indicating a period during which the content is permitted to be played back; and

a playback control unit operable to permit the content to be played back during the period indicated by the period information, and prohibit the content from being played back after the period indicated by the period information ends,

wherein, after the period indicated by the period information ends, the playback control unit (i) maintains the content and the content information stored in the storage unit until a suspension period ends, and (ii) deletes the content and the content information from the storage unit after the suspension period ends,

wherein the backup device includes;

a content receiving unit operable to receive the content from the recording/playback device;

a backup storage unit operable to store the received content;

an extension request receiving unit operable to receive an extension request to permit an extension of the period during which the content stored in the recording/playback device is permitted to be played back, the extension request being received from the recording/playback device;

a judging unit operable to judge whether or not to permit the extension; and

a permission unit operable to output, to the recording/playback device, extension permission information to permit the extension of the period, if the judging unit judges to permit the extension,

wherein the backup storage unit further stores detection information in correspondence with the received content, the detection information being generated by performing a predetermined calculation on the received content,

wherein the judging unit reads the received content from the backup storage unit, generates verification information by performing the predetermined calculation on the received content read from the backup storage unit, compares the generated verification information with the detection information, and judges to permit the extension if the generated verification information matches the detection information,

wherein the extension request contains device identification information that identifies the recording/playback device, and

wherein the judging unit preliminarily stores one or more pieces of approved device identification information that respectively identifies one or more predetermined devices, and judges to permit the extension if the device identification information contained in the received extension request matches any of the one or more pieces of approved device identification information.

2. The backup system of claim 1,

wherein the recording/playback device further includes:

an extension request unit operable to transmit to the backup device the extension request to permit the extension of the period indicated by the period information; and

an extension unit operable to receive, from the backup device, the extension permission information to permit the extension of the period, and extend the period indicated by the period information.

3. The backup system of claim 2, wherein

the extension request unit transmits the extension request during a predetermined time period before a point of time when the period indicated by the period information ends.

4. The backup system of claim 2, wherein

the extension request unit transmits the extension request repeatedly at regular intervals during the period indicated by the period information.

5. The backup system of claim 2, wherein

the extension unit extends the period indicated by the period information by receiving the extension permission information, the extension permission information indicating another period that is later than the period indicated by the period information stored in the storage unit, and

the extension unit rewrites the period indicated by the period information to be the other period indicated by the extension permission information.

6. The backup system of claim 2, wherein

the extension unit preliminarily stores an extension time period, and extends the period indicated by the period information by adding the extension time period to the period indicated by the period information.

7. The backup system of claim 2, wherein

the period information indicates a point of time when the period, during which the content stored in the storage unit is permitted to be played back, ends, and

the playback control unit permits the content to be played back if a current time is before the point of time indicated by the period information, and prohibits the content from being played back if the current time is after the point of time indicated by the period information.

8. The backup system of claim 2, wherein

the period information is composed of (i) a permission time period that indicates a length of time during which the content stored in the storage unit is permitted to be played back, and (ii) a start time that indicates a point of time at which the period, during which the content is permitted to be played back, starts, and

the playback control unit obtains an elapsed time since the start time, permits the content to be played back if the obtained elapsed time is not greater than the permission time period, and prohibits the content from being played back if the obtained elapsed time is greater than the permission time period.

9. The backup system of claim 1, wherein

the playback control unit prohibits the content from being played back by deleting the content from the storage unit.

10. The backup system of claim 9,

wherein the recording/playback device further includes:

a restore instruction obtaining unit operable to obtain a restore instruction to obtain the content stored in the backup device;

a restore request unit operable to, if the restore instruction obtaining unit obtains the restore instruction, transmit to the backup device a transmission request to transmit the content stored in the backup device; and

a restore unit operable to receive the content from the backup device and write the received content into the storage unit,

wherein, after the received content is written into the storage unit, the writing unit writes period information to the storage unit in correspondence with the received content, and

wherein the period information, stored in correspondence with the received content, indicates a period during which the received content, which was written into the storage unit by the restore unit, is permitted to be played back.

11. The backup system of claim 1, wherein

the content stored in the storage unit includes an encrypted work and a decryption key, the encrypted work having been generated by encrypting a digital work using an encryption key, the decryption key being used for decrypting the encrypted work, and

the playback control unit prohibits the content from being played back by deleting the decryption key contained in the content.

12. The backup system of claim 11,

wherein the recording/playback device further includes:

a restore instruction obtaining unit operable to obtain a restore instruction to obtain the decryption key stored in the backup device;

a restore request unit operable to, if the restore instruction obtaining unit obtains the restore instruction, transmit to the backup device a transmission request to transmit the decryption key stored in the backup device; and

a restore unit operable to receive the decryption key from the backup device and write the received decryption key into the storage unit,

wherein, when the received decryption key is written into the storage unit, the writing unit writes period information to the storage unit in correspondence with the content including the encrypted work and the received decryption key, and

wherein the period information, written in correspondence with the content key including the encrypted work and the received decryption key, indicates a period during which the content including the encrypted work and the received decryption key stored in the storage unit is permitted to be played back.

13. The backup system of claim 1, wherein

the content stored in the storage unit includes an encrypted work and an encrypted key, the encrypted work having been generated by encrypting a digital work using an encryption key, the encrypted key having been generated by encrypting a decryption key, which is used for decrypting the encrypted work, using a unique key that is unique to the recording/playback device, and

the playback control unit prohibits the content from being played back by deleting the encrypted key from the storage unit.

14. The backup system of claim 1, wherein

the content stored in the storage unit includes backup information that indicates a permission or a prohibition of a backup,

the content transmitting unit judges whether the backup information indicates the permission or the prohibition of the backup, and transmits the content if it is judged that the backup information indicates the permission of the backup, and

the writing unit judges whether the backup information indicates the permission or the prohibition of the backup, and writes the period information if it is judged that the backup information indicates the permission of the backup.

15. The backup system of claim 1, wherein

the content transmitting unit generates an encrypted content by encrypting the content using a communication key, and transmits the encrypted content safely.

16. The backup system of claim 1,

wherein the recording/playback device further includes:

a detection information storage unit storing detection information that is generated by performing a predetermined calculation on the content; and

an unauthorized use prohibition unit operable to read the content from the storage unit, generate verification information by performing the predetermined calculation on the content read from the storage unit, compare the generated verification information with the detection information, and prohibit the content from being used if the generated verification information does not match the detection information.

17. The backup system of claim 1,

wherein the backup device stores another content as a result of an execution of a backup instruction by a device other than the recording/playback device,

wherein the recording/playback device further includes:

a restore instruction obtaining unit operable to obtain a restore instruction to obtain the other content;

a content request unit operable to, if the restore instruction obtaining unit obtains the restore instruction, transmit to the backup device a transmission request to transmit the other content; and

a restore unit operable to receive the other content from the backup device and write the received other content into the storage unit,

wherein, when the other content is received, the writing unit writes period information to the storage unit in correspondence with the other content, and

wherein the period information, stored in correspondence with the other content, indicates a period during which the other content is permitted to be played back.