Information recording/playback apparatus and method
First Claim
1. An information recorder for recording information to a recording medium, the apparatus comprising:
- a transport stream processing means for appending an arrival time stamp (ATS) to each of discrete transport packets included in a transport stream; and
a cryptography means for generating a block key for encrypting a block data including more than one transport packet each having the appended arrival time stamp (ATS) from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and encrypting each block data with the block key thus generated;
the data encrypted by the cryptography means being recorded to the recording medium.
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Accused Products
Abstract
A block key to encrypt block data is generated using an ATS (arrival time stamp) appended to each of TS (transport stream) packets included in a transport stream correspondingly to the arrival time of the TS packet. The ATS is a random data depending upon an arrival time, and so a block-unique key can be generated, which enhances the protection against data cryptanalysis. A block key is generated from a combination of an ATS with a key unique to a device, recording medium or the like such as a master key, disc-unique key, title-unique key or the like. Since an ATS is used to generate a block key, any area for storage of an encryption key for each block may not be provided in a recording medium.
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Citations
47 Claims
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1. An information recorder for recording information to a recording medium, the apparatus comprising:
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a transport stream processing means for appending an arrival time stamp (ATS) to each of discrete transport packets included in a transport stream; and
a cryptography means for generating a block key for encrypting a block data including more than one transport packet each having the appended arrival time stamp (ATS) from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and encrypting each block data with the block key thus generated;
the data encrypted by the cryptography means being recorded to the recording medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An information player for playing back information from a recording medium, the apparatus comprising:
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a cryptography means for decrypting encrypted data recorded in the recording medium by generating a block key for decrypting encrypted data of a block data having an arrival time stamp (ATS) appended to each of a plurality of transport packets from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and decrypting each block data with the block key thus generated; and
a transport stream processing means for controlling data output on the basis of the arrival time stamp (ATS) appended to each of the plurality of transport packets included in the block data having been decrypted by the cryptography means. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method for recording information to a recording medium, the method comprising the steps of:
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appending an arrival time stamp (ATS) to each of discrete transport packets included in a transport stream; and
generating a block key for encrypting a block data including more than one transport packet each having the appended arrival time stamp (ATS) from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and encrypting each block data with the block key thus generated;
the data encrypted in the cryptographic step being recorded to the recording medium. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A method for playing back information from a recording medium, the method comprising the steps of:
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generating a block key for decrypting encrypted data in a block data having an arrival time stamp (ATS) appended to each of a plurality of transport packets from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and decrypting each block data with the block key thus generated; and
processing a transport stream processing means to control data output on the basis of the arrival time stamp (ATS) appended to each of the plurality of transport packets included in the block data having been decrypted in the decrypting step. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A recording medium having recorded therein a block data including more than one packet included in a transport stream and having an arrival time stamp (ATS) appended to each of the packets, the block data including:
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an unencrypted data part having a block seed including the arrival time stamp (ATS) from which there is generated a block key for encrypting the block data; and
an encrypted data part having been encrypted with the block key.
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46. A program serving medium which serves a computer program under which recording of information to a recording medium is done in a computer system, the computer program comprising the steps of:
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appending an arrival time stamp (ATS) to each of discrete transport packets included in a transport stream; and
generating a block key for encrypting a block data including more than one transport packet each having the appended arrival time stamp (ATS) from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and encrypting each block data with the block key thus generated.
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47. A program serving medium which serves a computer program under which playback of information from a recording medium is done in a computer system, the computer program comprising the steps of:
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generating a block key for decrypting encrypted data in a block data having an arrival time stamp (ATS) appended to each of a plurality of transport packets from a block seed which is additional information unique to the block data and including the arrival time stamp (ATS), and decrypting each block data with the block key thus generated; and
processing a transport stream to control data output on the basis of the arrival time stamp (ATS) appended to each of the plurality of transport packets included in the block data having been decrypted in the cryptographic step.
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Specification