Recording Device, Recording Medium, and Content Protection System
First Claim
1. A recording apparatus for transferring a usage right of a content to an external recording medium while protecting a copyright of the content, comprising:
- a storage unit operable to store (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents;
a key transfer unit operable to write the content key to the external recording medium, and erase the content key stored in the storage unit; and
a content transfer unit operable, after the content key has been erased, to write the second encrypted content to the external recording medium, and erase the second encrypted content from the storage unit.
2 Assignments
0 Petitions
Accused Products
Abstract
A recording/playback apparatus is capable of using pre-image-converted content in a case of transferring an image-converted content to another device, then back from transfer-destination device to the recording/playback apparatus. The recording/playback apparatus includes a storage unit that stores a first encrypted content generated by encrypting the content, a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and a content key for decryption of the first and second encrypted contents, a key transfer unit that writes the content key to the external recording medium, and erases the content key stored in the storage unit, and a content transfer unit that, after the content key has been erased, writes the second encrypted content to the external recording medium, and erases the second encrypted content from the storage unit.
32 Citations
17 Claims
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1. A recording apparatus for transferring a usage right of a content to an external recording medium while protecting a copyright of the content, comprising:
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a storage unit operable to store (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents;
a key transfer unit operable to write the content key to the external recording medium, and erase the content key stored in the storage unit; and
a content transfer unit operable, after the content key has been erased, to write the second encrypted content to the external recording medium, and erase the second encrypted content from the storage unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A content protection system for transferring a usage right of a content from a recording apparatus to an external recording medium while protecting a copyright of the content,
the recording apparatus including: -
a storage unit operable to store (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents;
a key transfer unit operable to write the content key to the external recording medium, and erase the content key stored in the storage unit; and
a content transfer unit operable, after the content key has been erased, to write the second encrypted content to the external recording medium, and erase the second encrypted content from the storage unit, and the recording medium including a storage area operable to store the content key and the second encrypted content.
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14. A portable recording medium for receiving a transfer of a usage right of a content from a recording apparatus while protecting a copyright of the content,
the recording apparatus including: -
a storage unit operable to store (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents;
a key transfer unit operable to write the content key to the external recording medium, and erase the content key stored in the storage unit; and
a content transfer unit operable, after the content key has been erased, to write the second encrypted content to the external recording medium, and erase the second encrypted content from the storage unit, and the recording medium including a storage area operable to store the content key and the second encrypted content.
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15. A content transfer method used in a recording-apparatus for transferring a usage right of a content to an external recording medium while protecting a copyright of the content,
the recording apparatus storing in a storage unit (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents, the content transfer method comprising: -
a key transfer step of writing the content key to the external recording medium, and erasing the content key stored in the storage unit; and
a content transfer step of, after the content key has been erased, writing the second encrypted content to the external recording medium, and erasing the second encrypted content from the storage unit.
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16. A content transfer program used in a recording apparatus for transferring a usage right of a content to an external recording medium while protecting a copyright of the content,
the recording apparatus storing in a storage unit (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents, the content transfer program comprising: -
a key transfer step of writing the content key to the external recording medium, and erasing the content key stored in the storage unit; and
a content transfer step of, after the content key has been erased, writing the second encrypted content to the external recording medium, and erasing the second encrypted content from the storage unit.
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17. A computer-readable recording medium having recorded thereon a content transfer program used in a recording apparatus for transferring a usage right of a content to an external recording medium while protecting a copyright of the content,
the recording apparatus storing in a storage unit (i) a first encrypted content generated by encrypting the content, (ii) a second encrypted content generated by performing an irreversible compression to convert the content, thereby obtaining a converted content, and by encrypting the converted content, and (iii) a content key for decryption of the first and second encrypted contents, the content transfer program comprising: -
a key transfer step of writing the content key to the external recording medium, and erasing the content key stored in the storage unit; and
a content transfer step of, after the content key has been erased, writing the second encrypted content to the external recording medium, and erasing the second encrypted content from the storage unit.
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Specification