To determine whether or not a correct continuous reproduction disk has been attached, and perform control in accordance with a determination result in a data reproduction process including a first information recording medium and a second information recording medium. A first root certificate transform value is calculated by applying a first transform function to data constituting a first root certificate recorded in the first information recording medium and a second root certificate transform value is calculated by applying a second transform function to data constituting a second root certificate recorded in the second information recording medium. Transform values based on first and second root certificates are compared. A process under execution is continued when the first and second root certificate transform values match. However, the process under execution is stooped or a warning is output when the first and second root certificate transform values do not match.

A digital information recording apparatus includes a recording circuit for recording information of a retention period included in the digital information and indicating a period for permitting the digital information to be held in the recording medium, starting with a time at which the digital information is recorded on the recording medium; and information of a playback permission period included in the digital information and indicating a period for permitting the digital information to be played back starting with a time at which the information is reproduced initially following recording of the digital information on the recording medium, permitting temporary recording or copying for the information permitted for copy never or copy one generation.

To determine whether or not a correct continuous reproduction disk has been attached, and perform control in accordance with a determination result in a data reproduction process including a first information recording medium and a second information recording medium. A first root certificate transform value is calculated by applying a first transform function to data constituting a first root certificate recorded in the first information recording medium and a second root certificate transform value is calculated by applying a second transform function to data constituting a second root certificate recorded in the second information recording medium. Transform values based on first and second root certificates are compared. A process under execution is continued when the first and second root certificate transform values match. However, the process under execution is stooped or a warning is output when the first and second root certificate transform values do not match.

A record (100) may include a disk (102), an embedded electronic authentication tag (104), a cover (106) between the disk and the electronic authentication tag, and one or more record labels (108A, 108B). The disk, electronic authentication tag, and cover have a spindle hole (114) and a common centerline (116). The electronic authentication tag contains a unique identification code pointing to information regarding the record stored as a non-fungible token. This information may be used to verify the authenticity and ownership of the record. A puck used to create the disk may include segments of different colors so that, when the record is pressed the different segments produce a visual pattern unique to that record. A picture may be taken after pressing, recorded, recorded as part of the information in the non-fungible token, and later used to verify the authenticity of the record.

A record (100) may include a disk (102), an embedded electronic authentication tag (104), a cover (106) between the disk and the electronic authentication tag, and one or more record labels (108A, 108B). The disk, electronic authentication tag, and cover have a spindle hole (114) and a common centerline (116). The electronic authentication tag contains a unique identification code pointing to information regarding the record stored as a non-fungible token. This information may be used to verify the authenticity and ownership of the record. A puck used to create the disk may include segments of different colors so that, when the record is pressed the different segments produce a visual pattern unique to that record. A picture may be taken after pressing, recorded, recorded as part of the information in the non-fungible token, and later used to verify the authenticity of the record.

Example systems, data storage devices, testers, and methods for storage device configuration using symbol context mutual information are described. A data storage device may include channel circuit configuration settings for the encoding and decoding of data written to a non-volatile storage medium. The configuration settings may be determined by determining a known pattern for a sector, determining a series of symbol contexts, determining mutual information for each symbol context, and using the symbol context mutual information to determine relationships among configuration settings, such as bit size, error correction code rate, and modulation code. Once determined, the configuration settings may be used to configure the modulation code and ECC rate for the channel circuit of the data storage device.

A record (100) may include a disk (102), an embedded electronic authentication tag (104), a cover (106) between the disk and the electronic authentication tag, and one or more record labels (108A, 108B). The disk, electronic authentication tag, and cover have a spindle hole (114) and a common centerline (116). The electronic authentication tag contains a unique identification code pointing to information regarding the record stored as a non-fungible token. This information may be used to verify the authenticity and ownership of the record. A puck used to create the disk may include segments of different colors so that, when the record is pressed the different segments produce a visual pattern unique to that record. A picture may be taken after pressing, recorded, recorded as part of the information in the non-fungible token, and later used to verify the authenticity of the record.

A record (100) may include a disk (102), an embedded electronic authentication tag (104), a cover (106) between the disk and the electronic authentication tag, and one or more record labels (108A, 108B). The disk, electronic authentication tag, and cover have a spindle hole (114) and a common centerline (116). The electronic authentication tag contains a unique identification code pointing to information regarding the record stored as a non-fungible token. This information may be used to verify the authenticity and ownership of the record. A puck used to create the disk may include segments of different colors so that, when the record is pressed the different segments produce a visual pattern unique to that record. A picture may be taken after pressing, recorded, recorded as part of the information in the non-fungible token, and later used to verify the authenticity of the record.

Example systems, data storage devices, testers, and methods for storage device configuration using mutual information are described. A data storage device may include channel circuit configuration settings for the encoding and decoding of data written to a non-volatile storage medium. Mutual information metrics may be calculated based on a multi-bit symbol size to compensate for inter-symbol interference and compared to mutual information thresholds to determine the configuration settings, such as bit and track densities, error correction codes, and modulation codes. Mutual information metrics may be used to characterize heads and media independent of the configuration settings.