Content reading apparatus

• US 20040228487A1
• Filed: 06/22/2004
• Published: 11/18/2004
• Est. Priority Date: 07/09/2001
• Status: Abandoned Application

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujimura, Kazuya, Nakamura, Norio, Maeda, Shigenori, Harada, Shunji, Senoh, Takanori
• Application Number:
  US10/482,969
• Publication Number:
  US 20040228487A1
• Time in Patent Office: Days
• US Class Current: 380/232
• 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 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G06F 2221/2129 Authenticate client device independently of the user
• CPC Class Codes: G06F 2221/2137 Time limited access, e.g. to a computer or data
• 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 20/00115 wherein the record carrier stores a unique medium identifier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00246 wherein the key is obtained from a local device, e.g. device key initially stored by the player or by the recorder
• CPC Class Codes: G11B 20/00362 the key being obtained from a media key block [MKB]
• CPC Class Codes: G11B 20/00528 wherein each title is encrypted with a separate encryption key for each title, e.g. title key for movie, song or data file
• CPC Class Codes: G11B 20/0084 wherein the usage restriction can be expressed as a specific time or date
• CPC Class Codes: G11B 20/00847 wherein the usage restriction is defined by a licence file
• CPC Class Codes: G11B 2020/10546 specifically adapted for audio data
• CPC Class Codes: G11B 2220/60 Solid state media details of solid state memory devices G11C

Abstract

A content reading apparatus only permits the use of contents such as images, music, and the like within a permitted usage period. In a recording medium having an authentication function, secure data that includes a decryption key and a remaining usage period is recorded in a protected area, and an encrypted content corresponding to the secure data is recorded in a user area. A decrypting of the encrypted content by a decryption unit, and an outputting of the decrypted content by an output unit to a user is only permitted for the duration that the usage rights judgment unit judges the remaining usage period to be greater than zero. The remaining usage period is updated by the usage rights judgment unit in accordance with a usage period of the content by the user and rewritten back into the protected area.

Claims

1. A content reading apparatus comprising:

a content reading unit operable to read a content from a recording medium that has recorded thereon the content and a piece of remaining usage period information showing a remaining usage period of the content, the recording medium including an authentication circuit for authenticating the content reading apparatus when the recording medium is connected thereto, and a protected area in which the remaining usage period information is recorded and which is accessible by the content reading apparatus only when the content reading apparatus has been authenticated by the authentication circuit;

a remaining usage period information reading unit operable to read the remaining usage period information from the recording medium;

a content output unit operable to output the read content to an external apparatus; and

an output termination unit operable to terminate the content output if an elapsed period from a start of the content output is equal to or exceeds the remaining usage period shown in the read remaining usage period information.

2. The content reading apparatus of claim 1, further comprising:

an update unit operable to update the remaining usage period information so as to show the remaining usage period as being less than the difference between the remaining usage period shown in the remaining usage period information prior to the updating and an output period from the start of the content output until a time of the updating, wherein

the output termination unit terminates the content output when the elapsed period from the start of the content output is equal to or exceeds the remaining usage period shown in the remaining usage period information prior to the updating.

3. The content reading apparatus of claim 2, wherein

the update unit updates the remaining usage period information so as to show the remaining usage period as having a zero value, and at a completion of the content output, reupdates the remaining usage period information based on an output period from the start until the completion of the content output.

4. The content reading apparatus of claim 2, wherein

the update unit updates the remaining usage period information before a completion of a predetermined period of content output so as to show the remaining usage period as the difference between the remaining usage period shown in the remaining usage period information prior to the updating and the predetermined period of content output, and at a completion of the content output, reupdates the remaining usage period information based on an output period from the start until the completion of the content output.

5. The content reading apparatus of claim 1, further comprising:

an update unit operable to update the remaining usage period information for every lapse of a predetermined update period so as to show the remaining usage period as being the difference between the remaining usage period shown in the remaining usage period information prior to the updating and the predetermined update period, wherein

the output termination unit terminates the content output when the elapsed period from the start of the content output is equal to or exceeds the remaining usage period shown in the remaining usage period information prior to the updating.

6. The content reading apparatus of any of claims 3 to 5 further comprising:

a termination instruction reception unit operable to receive an instruction from a user to terminate the content output, wherein

the output termination unit terminates the content output when a termination instruction is received by the termination instruction reception unit, even if the elapsed period since the start of the content output is less than the remaining usage period shown in the read remaining usage period information, and

the update unit reupdates, at a time of the reception of the termination instruction from the user, the remaining usage period information based on an output period from the start of the content output until the reception of the termination instruction.

7. The content reading apparatus of claim 1, wherein

the recording medium has recorded thereon a plurality of contents and plural pieces of remaining usage period information that correspond one-to-one with the plurality of contents, and

the output termination unit terminates the content output if the elapsed period from the start of the content output is equal to or exceeds the remaining usage period shown in a corresponding piece of remaining usage period information.

8. The content reading apparatus of claim 1, wherein

the recording medium has recorded thereon a plurality of contents and plural pieces of remaining usage period information that correspond (i) one-to-one with the plurality of contents, (ii) to a selected plurality of the contents, or (iii) one-to-one with the plurality of contents and to a selected plurality of the contents,

the content reading apparatus further comprises:

a remaining usage period calculation unit operable to sum a remaining usage period shown in one piece of remaining usage period information and a remaining usage period shown in another piece of remaining usage period information.

9. The content reading apparatus of claim 1, wherein

the recording medium has recorded thereon a plurality of contents and plural pieces of remaining usage period information that correspond one-to-one with the plurality of contents,

the plurality of contents is recorded on the recording medium in encrypted form,

the recording medium has further recorded thereon a plurality of decryption keys that correspond one-to-one with the encrypted contents,

the content reading apparatus further comprises:

a decryption unit operable to decrypt each encrypted content using the decryption key corresponding to the encrypted content, and

the content output unit outputs the decrypted content to the external apparatus.

10. The content reading apparatus of claim 1, wherein

the recording medium includes a user area that has recorded therein the plurality of encrypted contents,

a plurality of decryption keys corresponding one-to-one with the plurality of encrypted contents are recorded in the protected area together with plural pieces remaining usage period information corresponding one-to-one with the plurality of encrypted contents,

the content reading apparatus further comprises:

a decryption unit operable to decrypt each encrypted content using the decryption key corresponding to the encrypted content, and

the content output unit outputs the decrypted content to the external apparatus.

11. A content reproduction apparatus comprising:

a content reading unit operable to read a content from a recording medium that has recorded thereon the content and a piece of remaining usage period information showing a remaining usage period of the content, the recording medium including an authentication circuit for authenticating the content reproduction apparatus when the recording medium is connected thereto, and a protected area in which the remaining usage period information is recorded and which is accessible by the content reproduction apparatus only when the content reproduction apparatus has been authenticated by the authentication circuit;

a remaining usage period information reading unit operable to read the remaining usage period information from the recording medium;

a reproduction unit operable to reproduce the read content; and

a reproduction termination unit operable to terminate the content reproduction if an elapsed period from a start of the content reproduction is equal to or exceeds the remaining usage period shown in the read remaining usage period information.

12. A computer program for having a content reading apparatus that includes a CPU control a content output, comprising:

a content reading step of reading a content from a recording medium that has recorded thereon the content and a piece of remaining usage period information showing a remaining usage period of the content, the recording medium including an authentication circuit for authenticating the content reading apparatus when the recording medium is connected thereto, and a protected area in which the remaining usage period information is recorded and which is accessible by the content reading apparatus only when the content reading apparatus has been authenticated by the authentication circuit;

a remaining usage period information reading step of reading the remaining usage period information from the recording medium;

a content output step of outputting the read content to an external apparatus; and

an output termination step of terminating the content output if an elapsed period from a start of the content output is equal to or exceeds the remaining usage period shown in the read remaining usage period information.

13. A computer-readable storage medium storing a computer program for having a content reading apparatus that includes a CPU control a content output, the computer program comprising:

a content reading step of reading a content from a recording medium that has recorded thereon the content and a piece of remaining usage period information showing a remaining usage period of the content, the recording medium including an authentication circuit for authenticating the content reading apparatus when the recording medium is connected thereto, and a protected area in which the remaining usage period information is recorded and which is accessible by the content reading apparatus only when the content reading apparatus has been authenticated by the authentication circuit;

a remaining usage period information reading step of reading the remaining usage period information from the recording medium;

a content output step of outputting the read content to an external apparatus; and

an output termination step of terminating the content output if an elapsed period from a start of the content output is equal to or exceeds the remaining usage period shown in the read remaining usage period information.