Information playing/reproducing apparatus and method
AssigneeSony Corporation
InventorsTomoyuki Asano, Yoshitomo Osawa, Motoki Kato
Life of this patent
Estimating the term…
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.
Claims20
An information player for playing back information from a recording medium, the information player comprising:
- 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.
A method for playing back information from a recording medium, the method comprising the steps of:
- 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.
A non-transitory computer readable storage medium that stores a program, which when executed by a computer, causes the computer to perform a method of playback of information from a recording medium comprising the steps of:
- 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 decrypting step.
Dependencies are inferred from the claim text.