Abstract: An optical disk is provided that disables reproduction of sub-information even if the sub-information as a contents encryption key is recorded entirely onto another optical disk. Sub-information is recorded on the optical disk by deforming a recording mark slightly in accordance with a pseudo random number sequence that is obtained using as an initial value medium ID that is read out medium inherent information. This allows sub-information inherent in a medium to be recorded, and even if the sub-information is duplicated entirely to another optical disk, the illegally duplicated sub-information cannot be reproduced because of a difference in initial value of a pseudo random number sequence between media.

Abstract: A recording apparatus for recording a duplicate of a product onto a recording medium, the product being a copyrighted digital product having a copy attribute embedded as a watermark thereon and the recording apparatus including (a) an acquiring unit for acquiring the copy attribute embedded on the product, (b) a changing unit for changing the acquired copy attribute into a copy attribute showing no more copy when the acquired copy attribute shows one generation copy, (c) a reading unit for reading from the recording medium at least a part of medium ID information recorded on the recording medium in an unalterable state, and (d) a recording unit for recording onto the recording medium the duplicate having both the copy attribute showing no more copy and the read medium ID information embedded as a watermark thereon.

Abstract: A recording type optical disk on which data is recordable includes a data recording and reproducing area for recording data therein and reproducing data therefrom, and a read-only disk identification information area for recording disk identification information for identifying the optical disk therein. In the optical disk, the disk identification information is formed by removing a reflection film that is formed on the optical disk in a strip shape. The disk identification information includes an inherent disk identifier for each optical disk, and the data recording and reproducing area includes an area for recording encrypted data therein. The encrypted data is encrypted by using information including the disk identification information for identifying the optical disk as a key.

Abstract: A recording type optical disk on which data is recordable includes a data recording and reproducing area for recording data therein and reproducing data therefrom, and a read-only disk identification information area for recording disk identification information for identifying the optical disk therein. In the optical disk, the disk identification information is formed by removing a reflection film that is formed on the optical disk in a strip shape. The disk identification information includes an inherent disk identifier for each optical disk, and the data recording and reproducing area includes an area for recording encrypted data therein. The encrypted data is encrypted by using information including the disk identification information for identifying the optical disk as a key.

Abstract: The present invention has an objective of realizing compatibility of an optical disk having a high resolution video signal recorded thereon and a system for reproducing the optical disk, with a conventional system for producing a standard resolution video signal. A high resolution video signal is divided by video division means into a main signal and a sub signal, and the main signal and the sub signal are MPEG-encoded. The stream of the main signal and the stream of the sub signal are divided into 1 GOP or more of frames. First interleave blocks 54 each including 1 GOP or more of the stream of the main signal and second interleave blocks 55 each including 1 GOP or more of the stream of the sub signal are recorded on an optical disk 1. A high resolution reproduction apparatus reproduces both the first and second interleave blocks to obtain a high resolution video output.

Abstract: An optical disc having a plurality of sectors, each of which includes a plurality of frames. Sub information bit value “0” or “1” is assigned to the plurality of frames constituting a sector, excluding the first and last frames. Edge positions are displaced so that leading/lagging errors appear in accordance with a certain rule when data fields of the frames to which sub information bit value “1” is assigned are read. Edge positions are displaced so that leading/lagging errors appear in accordance with a reversed rule of the certain rule when data fields of the frames to which sub information bit value “0” is assigned are read.

Abstract: The present invention has an objective of realizing compatibility of an optical disk having a high resolution video signal recorded thereon and a system for reproducing the optical disk, with a conventional system for producing a standard resolution video signal. A high resolution-video signal is divided by video division means into a main signal and a sub signal, and the main signal and the sub signal are MPEG-encoded. The stream of the main signal and the stream of the sub signal are divided into 1 GOP or more of frames. First interleave blocks 54 each including 1 GOP or more of the stream of the main signal and second interleave blocks 55 each including 1 GOP or more of the stream of the sub signal are recorded on an optical disk 1. A high resolution reproduction apparatus reproduces both the first and second interleave blocks to obtain a high resolution video output.

Abstract: A digital work (102) and copyright management information (103) for the digital work are recorded on an information recording medium (101) by altering a shape, a position or a pattern (104, 105) of recording mark edges of the digital work. Alternatively, a decryption key for the right management information is recorded on an information recording medium on which the copyright management information has been recorded encrypted, by altering the recording mark edges of the copyright management information. Alternatively, a check code for the copyright management information is recorded on the information recording medium by altering the recording mark edges. The check code is checked when the copyright management information is read, thus detecting illegal use of the copyright management information.

Abstract: An encryption apparatus 100a is comprised of the following: a CRL storage unit 111 that stores a CRL; a device key ring storage unit 112 that stores a device key KD_A specific to each copyright protection module 210a used by a decryption apparatus 200a; a content key storage unit 113 that stores a content key Kc that is a secret key for encrypting a content; a hashing function processing unit 114 that calculates a hash value of the CRL stored in the CRL storage unit 111 according to a hashing function; an Ex-OR unit 115 that obtains an exclusive OR value between the hash value and the device key KD_A; and an Enc unit 116 that encrypts the content key Kc using an output value from the Ex-OR unit, and stores the hash value, the encrypted content key and the encrypted content in a DVD2a.

Abstract: An encryption device, a decrypting device, a secret key generation device, a copyright protection system and a cipher communication device comprise: a CRL memory unit 111 that memorizes a CRL, a device key ring memory unit 112 that memorizes a peculiar device key KD A in every IC card 210a used in a decrypting device 200a, a content key memory unit 113 that memorizes a content key Kc which is a secret key for decrypting content, a hashing function processing unit 114 that calculates a hashing value of the CRL memorized in the CRL memory unit 111, an Ex-OR unit 115 that carries out an exclusive OR between the hashing value and the device key KD A memorized in the device key ring memory unit 112, and an Enc unit 116 that encrypts the content key Kc memorized in the content key memory unit 113 with an output value of an Ex-OR unit 115.

Abstract: Four ECC blocks are recorded in a burst cutting area of an optical disc. Each ECC block is constituted by a BCA content code of 1 byte, content data length of 1 byte, and content data of 14 bytes. Of the BCA content data, the leading 6 bits are used for application ID and the remaining 2 bits are used for block number. Disc ID is stored in the content data. Since the four ECC blocks exist, the optical disc can be managed individually by four applications at the maximum. Thus it becomes possible to manage the same optical disc by a plurality of applications.

Abstract: An optical disk according to the present invention is the optical disk on which secret information on unique information given to a specific optical disk manufacturer or a specific optical disk and information recorded on an infringement disk list of identifying an illegitimate optical disk manufacturer or an illegitimate optical disk are recorded in advance, and the optical disk has an area in which reproduction-only encrypted data encrypted based on the secret information and the information on the infringement disk list is recorded in advance or an area capable of recording the encrypted data to be encrypted based on the secret information and the information on the infringement disk list.

Abstract: A recording apparatus includes a disc recording unit for recording each video section composing a broadcast program onto a rewritable optical disc; an electronic watermark reading unit for reading electronic watermarks embedded into the video section; and a recording flag storing unit for storing a recording flag. If the read electronic watermarks show that recording is permitted, the recording flag is set as “0” to record the next video section. If the read electronic watermarks show that recording is prohibited, the recording flag is set as “1” not to record the next video section. If a broadcast program is newly selected under a condition where the recording of the currently received broadcast program is prohibited, the recording flag is reset to “0” and the first received video section of the newly selected broadcast program is recorded onto the rewritable optical disc.

Abstract: An ECC block is constituted by RS(248,216,33). Of a data length of 216 bytes (symbols), only 16 bytes are allocated to BCA data and the remaining 200 bytes are used for fixed data having a predetermined value. Using the fixed data of 200 bytes and the BCA data of 16 bytes, parities of 32 bytes (symbols) are caculated. Only the BCA data of 16 bytes and the parities of the former 16 bytes of the 32-byte parities, that is, a total of 32 bytes only, are recorded in a burst cutting area of an optical disc. In decoding, error correction processing is carried out by using the fixed data of 200 bytes. The unrecorded parities of 16 bytes are processed as having been erased. Thus the error correction capability in a burst cutting area of an optical disc can be improved.

Abstract: A content protection system prevents illegal key acquisition, without checking uniqueness of device keys. The content protection system includes a key data generation apparatus and a user terminal. The key data generation apparatus converts first key data, which is for using content, based on a predetermined conversion rule, thereby generating second key data, encrypts the second key data using a device key held by valid terminals, and outputs the encrypted key data. The user terminal obtains the encrypted key data, decrypts the encrypted key data using a device key held by the user terminal, thereby generating second key data, converts the second key data based on a re-conversion rule corresponding to the conversion rule, thereby generating the first key data, and uses the content with use of the generated first key data.

Abstract: DVD-Video discs and playback apparatuses are assigned a region code indicating one of six regions into which the world is divided, for the purpose of protecting copyrights of content such as movies and music. However, playback apparatuses exist that illegally circumvent the function of checking the region code of the disc with the region code of the playback apparatus.

Abstract: An authentication communication system is provided that is capable of storing information relating to revoked devices in less area than is conventionally required.

Abstract: An MPEG2-PS format digital stream is composed of VOBUs and each VOBU except an RDI-Pack at the top is encrypted using a content key Kc. The content key Kc is an encryption key obtained by adding a title key Kt to CCI, and then converting a time varying coefficient using the sum. Accordingly, the resulting content key Kc differs for each VOBU. Since each content key Kc is all different for such a small unit of VOBU, copyright of the digital stream is firmly protected. CCI contained in RDI-Pack represents conditional Copy Freely status which allows the digital stream to be copied on condition that the digital stream is recorded only in encrypted form.

Abstract: In an information input/output system, a user device inputs and outputs information to and from external sources including a key management device. The system includes the key management device that securely outputs invalid-device information specifying an invalid device unit that has been made invalid for use, and the user device that includes an input/output unit and a host unit. Via the input/output unit, input and output of information is enabled between the host unit and the external sources. The host unit securely receives, via the input/output unit, the invalid-device information outputted by the key management device and judges whether the input/output unit is an invalid device unit by referring to the received invalid-device information, and when judging affirmatively, thereafter prohibits input and output via the input/output unit. Due to this construction, the host unit can correctly judge whether the input/output unit is an invalid device unit.

Abstract: A revocation list generation apparatus and a revocation judgement apparatus suppress the size of a CRL even if a number of public key certificates to be revoked increases.