Victor Company of Japan, Limited

Jvc Kenwood Corporation

Kenjiro Ueda

Takayuki Sugahara

Seiji Higurashi

Toshio Kuroiwa

Wataru Inoha

Masayoshi Nishitani

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

Digital image data is divided, per frame, into 'N' fields. 'N/m' combinations of imperceptible codes are produced, each combination having &#x201c;m&#x201d; codes given by an inverse of a function giving an identification code with the &#x201c;m&#x201d; codes as variables. &#x201c;N&#x201d; and &#x201c;m&#x201d; are an integer of 2 or more and &#x201c;m&#x201d; is given by dividing &#x201c;N&#x201d; by an integer. The combinations are embedded into the data to embed the &#x201c;m&#x201d; codes of each combination into the data in &#x201c;m&#x201d; fields according to a rule of positional correspondence to give correlation among &#x201c;m&#x201d; fields in &#x201c;N&#x201d; fields. The data is divided into &#x201c;N&#x201d; fields and the codes are extracted therefrom and combined into the combinations according to the rule. An operation is conducted based on the function. It is determined that the data has not been tampered with only when the operation gives the identification code for each combination.

Recording and reproduction apparatus, recording and reproduction method, recording and reproduction program for imperceptible information to be embedded in digital image data

Digital video data is encryptically processed and then subjected to an encoding procedure with orthogonal transform to produce a coded video signal. A representative value of luminance of pixels of the digital video data is obtained for each of pixel blocks having a predetermined number of pixels, each pixel block corresponding to a unit of data subjected to the encoding procedure, as a quantized integer for each pixel block by using a specific function with the stored luminance data as a parameter. It is determined whether the quantized integer of the representative value for each pixel block is a multiple of a preset integer N of two or larger, and, if not, the stored luminance data are rewritten with a specific requirement giving the least range of change in gradation so that the quantized integer becomes a multiple of the integer N, whereas the stored luminance data remain unchanged if the quantized integer is a multiple of the integer N, thus the digital video data being encryptically processed. The encryptically processed digital video data is encoded with orthogonal transform to produce a coded video signal. The coded video signal is decoded. A second representative value of luminance data of the decoded signal is obtained as a quantized integer for each pixel block by using the specific function with the luminance data as the parameter. The quantized integer of the second representative value is divided by the integer N. It is determined that the video data has been tampered with when remainders of division meet predetermined tamer criteria.

Apparatus, method and program for data processing, and apparatus, method and program for tamper detection

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

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.

Growing community of inventors

Yokosuka, Japan

Kenjiro Ueda