Victor Company of Japan, Limited

Jvc Kenwood Corporation

Wataru Inoha

Takayuki Sugahara

Seiji Higurashi

Toshio Kuroiwa

Kenjiro Ueda

Shin Nakate

Video data pieces are classified into groups according to prescribed rules. A cut number assigned to each of the groups is decided on the basis of the length or lengths of a video data piece or pieces in each of the groups and the number of the video data piece or pieces in each of the groups. A cut or cuts are extracted from the video data piece or pieces in each of the groups. Regarding each of the groups, the number of the extracted cut or cuts is equal to the decided cut number. Digest data is generated from the extracted cuts for all the groups.

Method and apparatus for generating data representing digests of pictures

Executes a re-encoding after decoding data of a connection section A of a first MPEG picture data. This re-encoding is executed based on a control such that a transition of a VBV buffer occupation value starts from a VBV buffer occupation value at a position a and ends with a VBV buffer occupation value at a position d. Up to the position a of the first MPEG picture data, the first MPEG picture data is reproduced. Next, re-encoded MPEG picture data of the connection section A is reproduced. Thereafter, the data is connected to the position d of a second MPEG picture data, and the second MPEG picture data of the position d and after is reproduced.

MPEG picture data recording apparatus, MPEG picture data recording method, MPEG picture data recording medium, MPEG picture data generating apparatus, MPEG picture data reproducing apparatus, and MPEG picture data reproducing method

An encryption key is generated in response to a plurality of information pieces being bases for the encryption key. Original information is encrypted into encryption-resultant information in response to the generated encryption key. The encryption-resultant information is divided into units. Each of the units is loaded with encryption control information for identifying the plurality of information pieces being the bases for the encryption key.

Method and apparatus for encrypting and decrypting information

The present invention relates to an encryption method for encrypting information including a series of multiple unit blocks, one at a time, a decryption method for decrypting multiple encrypted unit blocks, one at a time, and a recording and reproducing apparatus that uses those methods. The seed of an encryption key for encrypting each unit block and the seed of an encryption key for decrypting each encrypted unit block, which are used by those methods and the recording and reproducing apparatus, are based on a unit block that is one or more unit blocks before the current unit block in a reproduction order or on information generated by encrypting one or more unit blocks before the current unit block. Alternatively, the seed of an encryption key for encrypting each unit block and the seed of an encryption key for decrypting each encrypted unit block are information based on an encryption key for encrypting a unit block before the current unit block in a reproduction order.

Encryption method, decryption method, and recording and reproducing apparatus

A recording apparatus generates key information based at least on contents reproduction permission information, encrypts contents based on the key information, and records the encrypted contents and recording date/time information on a recording medium. A reproducing apparatus reads the encrypted contents and the recording date/time information from the recording medium, acquires reproduction date/time information on the encrypted contents and, based on the recording date/time information that was read, the reproduction date/time information, and reproduction permission limit information on the encrypted contents, generates contents reproduction permission information indicating that the encrypted contents maybe reproduced. The reproducing apparatus generates key information based at least on the contents reproduction permission information and decrypts the encrypted contents that were read.

Contents recording apparatus, recording medium, contents reproducing apparatus, contents transmission method, transmission medium, and contents reception method

A first-key signal representative of a first key is generated from first-key base information being a base of the first key. Contents information is encrypted into encryption-resultant contents information in response to the first-key signal. A second-key signal representative of a second key is generated on the basis of initial-value information of a given initial value according to a predetermined key generation algorithm. The first-key base information is encrypted into encryption-resultant first-key base information in response to the second-key signal. The encryption-resultant contents information, the encryption-resultant first-key base information, the initial-value information, and algorithm identification information for identifying the predetermined key generation algorithm are transmitted or recorded.

Method and apparatus for contents information

Bits of a first bit sequence are rearranged in a first matrix according to a predetermined arrangement rule. The first bit sequence represents information being a base of a key. Blocks are formed in the first matrix. Each of the blocks has bits, the number of which is smaller than the number of bits composing the first matrix. Logical operation is executed among bits in each of the blocks, and a bit being a result of the logical operation is generated. The logical-operation-result bits are combined into a second bit sequence. The number of bits composing the second bit sequence is smaller than the number of bits composing the first bit sequence. There is a second matrix composed of predetermined third bit sequences. The second matrix is accessed and one is read out from among the third bit sequences in response to the second bit sequence. The read-out third bit sequence is outputted as information representative of the key. The number of bits composing each of the third bit sequences is smaller than the number of bits composing the second bit sequence.

Cryptosystem-related method and apparatus

After a user terminal executes a data usage accounting procedure for a contents provider, enciphered copyrighted digital data generated by enciphering chargeable copyrighted digital data using encryption key data, digital sample preview data generated from an outline of the copyrighted digital data at a non-chargeable level without enciphering, decryption key data for deciphering the enciphered copyrighted digital data, and additional data required for accounting are transmitted from the contents provider to the user terminal over a network.

Copyrighted digital data management method, contents provider, user terminal, and data recording medium

A signal representative of a key is generated from authenticator-value information and key base information. The authenticator-value information represents a specified authenticator value. The key base information contains identification information which is set to reproduce the specified authenticator value according to a predetermined degeneration function. Contents information is encrypted into encryption-resultant contents information in response to the key signal. The key base information and the encryption-resultant contents information are transmitted or recorded.

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Kanagawa-ken, Japan

Wataru Inoha