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; and
wherein the cryptography means generates a title-unique key from a key stored in the information recorder, disk ID and a title key unique to data to be recorded to the recording medium, andgenerates the block key from the title-unique key and block seed.
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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
40 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; and wherein the cryptography means generates a title-unique key from a key stored in the information recorder, disk ID and a title key unique to data to be recorded to the recording medium, and generates the block key from the title-unique key and block seed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. 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; and wherein the cryptography means generates a title-unique key from a key stored in the information recorder, disk ID and a title key unique to data to be recorded to the recording medium, and generates the block key from the title-unique key and block seed. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. 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; a title-unique key is generated from a key stored in the information recorder, disc ID and a title key unique to data to be recorded to the recording medium, and the block key is generated from the title-unique key and block seed. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. 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; wherein in the decrypting step, a title-unique key is generated from a key stored in the information player, disc ID and a title key unique to data to be recorded to the recording medium, and the block key is generated from the title-unique key and block seed. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40)
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Specification