JP2005250613A - Reproduction time management system, reproduction time management method, reproduction device, reproduction method and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To much more accurately execute time management for the reproduction permission/inhibition of main data to be recorded in a recording medium. <P>SOLUTION: Predetermined standard time information from an NTP server connected through a network is received by a standard time reception processing part, and the current time information measured by a time measuring part 30 is corrected according to this. Thus, it is possible to perform accurate reproduction time management based on the predetermined standard time received from the predetermined NTP server. Also, the reproduction time data to be recorded in a disk 100 are encrypted by a secret key among encryption keys generated by an asymmetrical encryption system. In this case, the public key making a pair with the secret key is preliminarily assigned at the reproduction divice 10 side, and the reproduction time data reproduced from the disk 100 is decoded by using the public key at a reproduction device 10 side. Thus, it is possible only for a person who owns a legal secret key to decode the reproduction time data by a reproducing device 10 side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a reproduction time management system and method for performing reproduction time management of the main data for a recording medium on which main data to be managed for permission / non-permission of reproduction is recorded, and the recording medium. The present invention relates to a playback apparatus and method for performing playback on a recording medium, and a recording medium.

Japanese Patent Laid-Open No. 10-341212 JP 2001-136161 A

  For example, software sales using recording media such as optical discs, music content and video content sales, so-called record sales and video sales are widely performed. In particular, with the spread of CDs (Compact Discs) and recently DVDs (Digital Versatile Discs), the distribution of video and music content by the digital recording method using optical disks has become more active.

However, as video / music contents are circulated through the digital recording system in this way, copyright infringement acts such as the manufacture and sale of pirated copies and illegal copying are becoming social problems.
For example, examples of illegal copying include music content and video content recorded on a ROM-type optical disc such as CD-ROM (CD-Video) and DVD-ROM (DVD-Video), CD-R, DVD-R, etc. Copying to a recordable type (Write Once type) optical disc is being carried out. This action is illegal if the user is not the owner of the ROM type optical disc.
For example, as a case of malicious copyright infringement, a pirated version manufacturing act is also performed in which a video content such as a movie is obtained from an unauthorized route, and the content is encoded and authored to produce a ROM type optical disc. Yes.

Conventionally, as a technology for protecting the copyright of content recorded on a recording medium such as an optical disc, for example, a time range in which reproduction of content is permitted / not permitted is recorded on the recording medium, and the playback device side There has been proposed a method of executing control for content reproduction based on the time range.
In other words, by defining a time range in which content playback is permitted / not permitted, for example, content playback is not permitted outside the specified range, thereby protecting copyright. .

In such a method, the playback device controls content playback based on the result of comparing the current time information measured by itself with the time range read from the recording medium.
However, the information on the current time measured on the playback device side at this time may be manually corrected by the user. Depending on this, the current time information may be falsified by the user. For this reason, for example, when control based solely on the current time information is performed, appropriate content reproduction based on the correct current time is performed. There is a possibility that management of the time cannot be performed.

For such a problem, Patent Document 1 described above can be cited.
In this patent document 1, as the first embodiment, “use time information is acquired from a data packet including a transmitted ciphertext, current time information is acquired from a clock 11, and use time information and current time information are acquired. Is determined. "Is disclosed. Further, in the second to fourth embodiments, in order to prevent tampering of the clock 11, “the value of the built-in clock 11 is written to the nonvolatile memory 14 for each set period, and the time stamp comparing unit 13 At the time when the determination process is performed, the storage time information from the nonvolatile memory 14 and the current time information from the built-in clock 11 are compared as a first comparison process. In the fifth embodiment and the sixth embodiment, “use position information is put in a data packet instead of time information, and the current position information is acquired from the built-in GPS 11 ′ in the ciphertext decryption apparatus”. Has been described.
According to the technique described in Patent Document 1, it is possible to detect that the value of the built-in clock 11 has been tampered in the middle, and for example, only when the current time information is correct, A comparison can be made to manage the content playback time.

Further, in the above-described Patent Document 2, as the second embodiment, “the time information recording unit 46 that stores the time information transmitted from the data reproducing device 110 is provided in the key storage device 40, and history information is stored in step S 204. If the latest time already stored in the storage unit 44 is compared with the key reading time stored in the time information storage unit 46, the key reading time indicates a time later than the latest time. In step S206, the key reading time is within the validity period of the playback device key stored in the validity period storage unit 43. It is confirmed whether or not there is. " Further, in the fifth embodiment, “By connecting signals from the real time measuring means 221 and the real position measuring means 222 to the data reproducing devices 204, 205, 206, correct real time information and real position information are inputted. A technique is disclosed that “a reproduction operation is performed only occasionally”.
Even when such a technique of Patent Document 2 is applied, since the time ranges can be compared in accordance with the fact that the current time information on the playback device side has not been tampered with, inaccurate content playback time management can be performed. It can be prevented from being performed. Furthermore, in this case, since the reproduction operation can be performed only when correct real time information is input, more accurate content reproduction time management can be performed.

In this way, as a method of managing the content reproduction time based on the time range information recorded on the recording medium, whether or not there is a possibility that the current time information has been falsified as in the above Patent Document 1. Also, by controlling the content reproduction, more accurate content reproduction time management can be achieved.
However, with the technique described in Patent Document 1, it is possible to check whether or not the current time information has been tampered with, but whether or not the current time information itself is adjusted to correct time information as a reference. I can't confirm. Then, according to this, as the information on the current time in this case, for example, it is confirmed whether or not it is set to a reference time (for example, Japan Standard Time) that is assumed by the package media sales side (ciphertext encryption device). In this respect, the content reproduction time management may become inaccurate.

However, according to the technique disclosed in the fifth embodiment of Patent Document 2 described above, the current time information can be adjusted to the actual time (standard time).
However, according to the description of the document, for realization, the real time measuring means 221 must be connected at the time of reproduction. It is not considered that the time measurement is not always possible.

For example, if the actual time cannot be measured as described above, it may be considered that the reproduction of the content data is not permitted because the current time is inaccurate, but in this way the actual time cannot be measured. However, there is a possibility that the current time is accurate. At this time, for example, if the current time is within the reproduction deadline, what should originally be permitted to be reproduced is not permitted.
In other words, when this is taken into account, there is a possibility that accurate reproduction time management cannot be performed by a method that does not consider that the actual time cannot always be measured.

On the other hand, as a method for managing the content playback time based on the time range information recorded on the recording medium as exemplified here, in addition to the current time information on the playback device side, There is a possibility that the information of the time range recorded in the above will be tampered with illegally.
And even if the time information recorded on the recording medium side is falsified in this way, it is naturally impossible to execute management in the time range intended on the content recording side (sales side) As a result, accurate playback time management cannot be performed.

For these reasons, it is difficult to perform accurate content playback time management based on appropriate time information as a conventional method for managing content playback time based on time range information recorded on a recording medium. It is in.
In other words, the method of managing the content playback time based on the time range information recorded on the recording medium provides a stronger copyright protection function that can always perform accurate content playback time management. It is requested.

Therefore, in the present invention, in view of the above problems, the first configuration of the reproduction time management system is as follows.
That is, as a playback time management system comprising a recording device and a playback device that perform recording and playback on a recording medium on which main data to be managed for playback permission / non-permission is recorded,
The recording device is
The recording medium includes recording means for recording reproduction time data for determining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data.
In addition, as the playback device,
First, reproduction means for reproducing data from the recording medium, standard time reception means for receiving standard time information generated by a predetermined external device connected via a network, and time measurement to generate current time information A time keeping means is provided.
In addition, time correction means for correcting the current time information based on at least the standard time information received by the standard time reception means, and further from the time when the standard time information was received in the past by the standard time reception means. When the error of the current time information based on the elapsed time is less than or equal to a predetermined value, the time range information indicated by the reproduction time data reproduced by the reproduction means is compared with the current time information. Based on the result, a reproduction control means for controlling the reproduction of the main data by the reproduction means is provided.

In the present invention, the first reproduction time management method is as follows.
That is, first, a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data for a recording medium on which main data to be managed for reproduction permission / non-permission is recorded. A recording procedure for recording reproduction time data for determining the recording time is executed.
Then, a standard time receiving procedure for receiving standard time information generated by a predetermined external device connected via the network and a time measuring procedure for performing timekeeping and generating current time information are executed.
In addition, a time correction procedure for correcting the current time information based on at least the standard time information received by the standard time reception procedure, and a process from the time when the standard time information was received in the past by the standard time reception procedure. A result of comparing the current time information with the information of the time range indicated by the reproduction time data reproduced from the recording medium in accordance with the case where the error of the current time information based on the time is equal to or less than a predetermined value And a reproduction control procedure for controlling the reproduction process of the main data.

Furthermore, in the present invention, the first configuration of the playback apparatus is as follows.
In other words, main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. A reproducing means for reproducing data from the recorded recording medium.
In addition, a standard time receiving unit that receives standard time information generated by a predetermined external device connected via a network, and a time measuring unit that measures time and generates current time information are provided.
In addition, time correction means for correcting the current time information based on at least the standard time information received by the standard time reception means, and further from the time when the standard time information was received in the past by the standard time reception means. When the error of the current time information based on the elapsed time is less than or equal to a predetermined value, the time range information indicated by the reproduction time data reproduced by the reproduction means is compared with the current time information. Based on the result, a reproduction control means for controlling the reproduction of the main data by the reproduction means is provided.

Furthermore, in the present invention, the first reproduction method is as follows.
In other words, main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. As a reproduction method for reproducing data from a recording medium, a standard time reception procedure for receiving standard time information generated by a predetermined external device connected via a network, and a time for generating current time information by measuring time And timekeeping procedures.
In addition, a time correction procedure for correcting the current time information based on at least the standard time information received by the standard time reception procedure, and a process from the time when the standard time information was received in the past by the standard time reception procedure. A result of comparing the current time information with the information of the time range indicated by the reproduction time data reproduced from the recording medium in accordance with the case where the error of the current time information based on the time is equal to or less than a predetermined value And a reproduction control procedure for controlling the reproduction process of the main data.

In the present invention, the first recording medium is as follows.
That is, the recording medium of the present invention is for determining the main data to be managed for permission / non-permission of reproduction and a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data. A recording medium on which playback time data is recorded,
Information on an error range relating to current time information measured by a reproducing apparatus that performs reproduction on the recording medium is recorded.

If the standard time information from the predetermined external device is received as in the first configuration of the present invention, accurate reproduction time management based on the predetermined standard time information by the external device can be realized. . At this time, for example, if information for designating an external device is recorded on a recording medium, and the playback device receives standard time information from the external device based on this designation information, the recording is surely performed. It is possible to realize reproduction time management based on a predetermined standard time intended by the device side (for example, the main data seller or copyright owner side).
In addition, according to the first configuration, when the error of the current time according to the elapsed time from the time received in the past is equal to or less than a predetermined value, the main data based on the comparison between the time range and the current time Reproduction control can be performed. According to this, even when the standard time information cannot be received at the time of reproduction of the main data, for example, the elapsed time since the reception of the standard time in the past is short and the current time is estimated to be correct with little error. In this case, it is possible to determine whether the main data is replayed based on the current time. That is, for example, even when the playback device cannot receive the standard time during playback of the main data, it is possible to determine whether playback is permitted or not based on the current time.
This makes it possible to perform more accurate reproduction time management than when the reproduction is not permitted immediately because the standard time is not received during reproduction of the main data, for example.

  In such a first configuration, for example, information on the error range for the current time information as described above is recorded on the recording medium side, and the error range is compared with the error on the current time on the playback device side. Depending on the result, if the main data playback control is performed based on the comparison between the above time range and the current time, the main data seller or copyright holder sets the error range allowed for the current time information. become able to.

In the present invention, the second configuration of the reproduction time management system is as follows.
That is, as a playback time management system comprising a recording device and a playback device that perform recording and playback on a recording medium on which main data to be managed for playback permission / non-permission is recorded,
The recording device is
Recording means for recording the reproduction time data for determining a time range based on a predetermined standard time for at least permission / non-permission of reproduction of the main data on the recording medium, and the reproduction time data, Recording control means is provided for performing control so as to be encrypted and recorded on the recording medium based on the secret key of the secret key and public key generated by the asymmetric encryption method.
In addition, as the playback device,
First, a reproducing unit that reproduces data from the recording medium and a time measuring unit that performs time measurement and generates current time information are provided.
Then, the playback time data played back by the playback means is decrypted using the public key previously assigned to the playback device, and the time indicated by the decrypted playback time data. Based on the result of comparing the range information and the current time information, a reproduction control means for controlling the reproduction of the main data by the reproduction means is provided.

In the present invention, the second reproduction time management method is as follows.
That is, first, for a recording medium on which main data to be managed for reproduction permission / non-permission is recorded, a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data. A recording procedure is executed for encrypting and recording the reproduction time data for determining the key based on the secret key of the secret key and the public key generated by the asymmetric encryption method.
Then, a time measuring procedure for generating time information by measuring time is executed, and then the reproduction time data reproduced from the recording medium is decrypted by using the public key assigned in advance. At the same time, based on the result of comparing the time range information indicated by the decoded reproduction time data with the current time information, a reproduction control procedure for controlling the reproduction process of the main data is executed.

Furthermore, in the present invention, the second configuration of the playback apparatus is as follows.
In other words, main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data. Reproduction of data from a recording medium on which the reproduction time data is encrypted and recorded based on the secret key of a secret key and a public key generated by an asymmetric encryption method. Reproducing means for performing is provided.
And a time measuring means for measuring time and generating current time information, and further, using the public key assigned to the reproducing apparatus in advance for the reproduction time data reproduced by the reproducing means. And a playback control means for controlling the playback of the main data by the playback means based on the result of comparing the time range information indicated by the decoded playback time data with the current time information. I prepared.

Furthermore, in the present invention, the second reproduction method is as follows.
That is, main data to be managed for permission / non-permission of reproduction, and reproduction time data for defining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data. Reproduction of data from a recording medium on which the reproduction time data is encrypted and recorded based on the secret key of a secret key and a public key generated by an asymmetric encryption method. As a playback method to perform,
First, a time measuring procedure is performed in which time is measured to generate current time information.
Then, the reproduction time data reproduced from the recording medium is decrypted using the public key assigned in advance, and information on the time range indicated by the decrypted reproduction time data and the current Based on the result of comparison with the time information, a reproduction control procedure for controlling the reproduction process of the main data is executed.

In the present invention, the second recording medium is as follows.
That is, the recording medium of the present invention defines main data to be managed for reproduction permission / non-permission, and at least a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data. As the recording medium on which the reproduction time data is recorded, the reproduction time data is recorded after being encrypted based on the secret key of the secret key and the public key generated by the asymmetric encryption method. .

According to the second configuration of the present invention, the reproduction time data is encrypted with a secret key by an asymmetric encryption method and recorded on a recording medium. Thus, the reproduction time data encrypted with the secret key can be decrypted only on the reproduction apparatus side to which the public key paired with the secret key is assigned in advance.
In other words, in order for the playback device to properly decrypt the encrypted playback time data, the playback time data must be encrypted with a pair of regular private keys, for example, playback time data. If an unauthorized recording medium in which data is tampered with and encrypted with an appropriate secret key is manufactured, it cannot be properly decrypted on the playback device side. That is, with such a mechanism, it is possible to eliminate an unauthorized recording medium in which the content of the reproduction time data is falsified.
At this time, for example, together with the reproduction time data, the partial data in the reproduction time data in plain text (before encryption) is recorded on the recording medium, and the reproduction apparatus side If the match with the partial data in the decrypted reproduction time data is compared, it is possible to determine whether or not the reproduction time data is encrypted with a regular secret key.

As described above, according to the first configuration of the present invention, it is configured to receive standard time information from a predetermined external device, so that accurate reproduction time management based on the predetermined standard time information by the external device can be performed. Can be realized. For example, if information for designating an external device is recorded on a recording medium, and the standard time information is received from the external device based on the designation information on the playback device side, the main data is surely obtained. Reproduction time management based on a predetermined standard time intended by the seller or the copyright owner.
As a result, it is possible to perform more accurate reproduction time management for the main data, and thus a stronger copyright protection function can be obtained.

Furthermore, according to the first configuration, for example, even when the standard time cannot be received during reproduction of the main data, if the error occurring in the current time information is equal to or less than a predetermined value, the current time and the reproduction time range are compared. Therefore, it is always possible to determine whether or not to allow reproduction when the error is less than a predetermined value and is accurate.
According to this, it is possible to achieve more accurate reproduction time management than in the case where reproduction is not permitted immediately when the standard time cannot be received at the time of reproduction of main data, for example. A right protection function can be realized.

In addition, according to the second configuration, since the reproduction apparatus cannot properly decrypt data other than the reproduction time data encrypted with the regular secret key, it is impossible to know the regular secret key. It is possible to prevent the playback time data recorded by the three parties from being properly decoded by the playback device. As a result, for example, it is difficult to manufacture an unauthorized recording medium in which the content of the reproduction time data has been altered by a third party, and the alteration of the content of the reproduction time data recorded on the recording medium is prevented.
By preventing falsification of the content of the playback time data in this way, it becomes possible to perform accurate content playback time management, and thus a stronger copyright on the main data recorded on the recording medium. The protection function can be realized.

  Further, in the second configuration, for example, a part of the reproduction time data in plain text before encryption is recorded as reproduction time recording data together with the reproduction time data on the recording medium, and the reproduction apparatus reproduces the above-mentioned reproduction data. If the content match between the partial data and the partial data in the decrypted playback time data is to be compared, it is possible to prove whether or not the playback time data is properly recorded. It becomes possible.

Embodiments of the present invention will be described below. The description will be given in the following order.
1. 1. Overview of playback time management system of embodiment 2. Configuration of recording apparatus 3. Configuration of playback device 1. First embodiment Second Embodiment 6. Third embodiment Fourth embodiment

1. Overview of playback time management system of the embodiment

FIG. 1 is a diagram showing an overview of a reproduction time management system 1 as an embodiment of the present invention.
First, the illustrated disc 100 is an optical disc medium such as a CD (Compact Disc) and a DVD (Digital Versatile Disc), and in this case, it is assumed that content data is recorded as video and / or audio data. Further, in this case, reproduction permission time data for managing the time at which reproduction of the content data is permitted / not permitted is recorded on the disc 100 as described later.
As the content data, other data such as an image may be recorded in addition to video and audio.

The recording device 50 records input data on the disc 100 in accordance with a required data recording format.
Further, the reproducing apparatus 10 reproduces data from the disc 100 on which data recording has been performed by the recording apparatus 50.
As will be described later, the playback device 10 in this case is configured to be able to communicate with an external device via the illustrated network 70 such as the Internet. The playback apparatus 10 is configured to receive standard time information generated by an NTP (Network Time Protocol) server 80 shown connected to the network 70.

Here, as a specific example of the NTP server 80 assumed to be used in the reproduction time management system 1 of the present embodiment, NTP (Network Time Protocol, RFC1305) or SNTP which is a simplified version of NTP is given. (Simple Network Time Protocol, RFC2030), and Time Protocol (RFC868).
Here, for confirmation, NTP is described in “Network Time Protocol (Version 3)” in RFC 1305 (Request For Comment 1305) issued by IETF (Internet Engineering Task Force) that standardizes technology on the Internet. Specification, Implementation and Analysis ”. In this technology, a server that provides current reference time information (standard time information) is prepared on the network, and the client communicates with the server once every few minutes to several hours or several days. The internal clock in the client is synchronized with the standard time information. In this protocol, the time can be synchronized with high accuracy, for example, by measuring the communication time between the server and the client.

  Similarly, the above SNTP is specified as “Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6, and OSI” in RFC 2030 (Request For Comment 2030) issued by the IETF. SNTP is a protocol that reduces the weight of NTP so that the client simply adjusts the time. Basically, the server requests standard time information from the server, and uses a response to the request for time adjustment.

  Similarly, the above Time Protocol is defined as “Time Protocol” in RFC868 (Request For Comment 868) issued by IETF. In this technology, for example, the server monitors the port 37 of TCP or UDP, and whether the client has connected to the port (in the case of TCP) or a datagram has arrived (in the case of UDP) In such a case, the standard time information with a 32-bit value is returned from the server. The client uses only this value as the current time and does not consider the communication time between the server and the client.

As a communication method related to standard time information between the NTP server 80 and the playback device 10 in the embodiment, for example, any one of them may be adopted and is not particularly limited.

2. Configuration of recording device

FIG. 2 is a block diagram showing an example of the internal configuration of the recording apparatus 50 shown in FIG.
The recording device 50 according to the embodiment includes an additional data input unit 51, a content source 52, a data formatter 53, and a mastering unit 54 as shown in the figure.
The additional data input unit 51 inputs additional data to be recorded on the master disc 99 (disc 100) in addition to the content data supplied from the content source 52. For example, management information for reproducing content data such as data necessary for drive control on the reproducing apparatus side and TOC (Table Of Contents) in the case of a CD is input. In the case of this example, the reproduction permission time data described above is input via this additional data input unit 51.

  The data formatter 53 is supplied with various additional data to be recorded on the disc 100 input via the additional data input unit 51 and content data from the content source 52. Then, the additional data and the content data are converted into a data format according to a predetermined recording format or modulation method, and supplied to the mastering unit 54.

  The mastering unit 54 irradiates a disc master 99 rotated by a spindle motor (not shown) with a laser beam based on data supplied from the data formatter 53, thereby forming a pit row in a spiral shape on the disc master 99. To do. As a result, the data supplied from the data formatter 53 is recorded on the disc master 99.

  Thus, the master disc 99 generated by the recording apparatus 50 is a master disc as a so-called glass master through development processing and electroforming processing. Then, a stamper is manufactured based on the disk master 99, a disk-shaped substrate is formed by molding using the stamper, and a disk 100 is manufactured by forming a reflective film and a protective film on the disk-shaped substrate. The

In this case, it is assumed that the recording device 50 has recorded the data that has been recorded on the disc 100 generated through the above-described process using the master disc 99 generated by the recording device 50. deal with.

3. Configuration of playback device

FIG. 3 is a block diagram showing an example of the internal configuration of the playback apparatus 10 as an embodiment.
First, the spindle motor 11 shown in the drawing rotates the loaded disk 100. Then, the pit data recorded on the disc 100 is read by the pickup 13.
The pickup 13 for performing a data reading operation from the disk 100 includes an optical system configured by a laser diode that performs laser output, an objective lens that serves as a laser output end, a polarization beam splitter, and the like, and detection of reflected light. Such as detectors.
In the pickup 13, the objective lens described above is held by a biaxial mechanism (not shown) so as to be able to shift in the disk radial direction (tracking direction) and in the direction in which it contacts and separates from the disk. The slider 14 can move in the radial direction of the disk.

Information detected from the disc 100 by the reproduction operation of the pickup 13 is supplied to the analog front end processor 16. The analog front end processor 16 includes an RF amplifier, a matrix arithmetic circuit, and a binarization circuit.
The information input to the analog front-end processor 16 is subjected to amplification processing, matrix calculation processing, binarization processing, etc., and is recorded and encoded by EFM (8/14 modulation) or EFMplus, EFM signal, EFMplus A signal (EFM +) is supplied to the CD / DVD processor 17.
At the same time, the analog front-end processor 16 generates a tracking error signal TE and a focus error signal TE based on information detected from the disc 100. Then, the tracking error signal TE, the focus error signal FE, and the EFM signal or EFMplus signal are supplied to a servo / PLL (Phase Locked Loop) circuit 15 shown in the figure.

The servo / PLL circuit 15 is based on the tracking error signal TE and the focus error signal FE supplied from the analog front-end processor 16 and the track jump command and access command from the system controller 24 connected via the internal bus 33. Various servo drive signals are generated to control the biaxial mechanism and the slide unit 14 in the pickup 13 to perform focus and tracking control.
The servo / PLL circuit 15 generates a reproduction clock based on the EFM signal / EFMplus signal supplied from the analog front-end processor 16. This recovered clock is output as a processing reference clock (master clock) for each part. The servo / PLL circuit 15 supplies the spindle motor driver 12 with a spindle servo control signal generated based on the reproduction clock and the EFM signal / EFMplus signal.

  The spindle motor driver 12 generates a motor drive signal based on the spindle servo control signal supplied from the servo / PLL circuit 15 and supplies it to the spindle motor 11. As a result, the spindle motor 11 rotates the disk 100 so as to obtain an appropriate rotation speed in accordance with a predetermined rotation control method.

The CD / DVD processor 17 performs demodulation processing on the EFM signal or EFMplus signal supplied from the analog front-end processor 16 and performs error correction and deinterleaving processing. That is, when the loaded disc 100 is a CD, the CD / DVD processor 17 performs EFM demodulation processing on the input signal, error correction processing based on CIRC (Cross Interleave Read-Solomon Code), and deinterleaving. To be processed. When the loaded disc 100 is a DVD, EFMplus demodulation processing for an input signal, error correction processing based on RS-PC (Read Solomon Product Code), and deinterleaving processing are performed.
Further, in the CD / DVD processor 17, for example, when the loaded disc 100 is a CD and the content data is only audio data, it is obtained through the above-described processes (demodulation, error correction, deinterleave processing). The supplied digital audio data is supplied to the audio D / A conversion circuit 19 via the internal bus 33.
When the loaded disc 100 is a DVD and the content data is AV data based on video data and audio data, the AV data obtained through each processing is sent to the demultiplexer 20 via the internal bus 33. Supply against.
Note that the switching of each operation based on the CD / DVD is performed based on the control of the system controller 24 connected via the internal bus 33, for example.
Further, based on the control of the system controller 24, the data obtained through the above processes is supplied to the host interface (I / F) 18 connected via the internal bus 33.

  The audio data D / A conversion circuit 19 performs D / A conversion processing on the digital audio data supplied from the CD / DVD processor 17 to obtain an analog audio signal output.

The demultiplexer 20 receives the AV data supplied from the CD / DVD processor 17 and performs video data / audio data separation processing.
The audio decoder 21 receives the audio data separated by the demultiplexer 20 and performs a decoding process. The digital audio data thus obtained is supplied to the audio D / A conversion circuit 19 described above.
The audio decoder 21 may be configured to support a 5.1 channel audio format such as DTS (Digital Theater System) in addition to a 2 channel audio format such as AC3 (Dolby Digital (2 channel)).

The video decoder 22 receives the video data separated by the demultiplexer 20 and performs a decoding process. The digital video data thus obtained is supplied to the NTSC / PAL encoder and D / A conversion circuit 23.
The NTSC / PAL encoder and D / A conversion circuit 23 encodes the supplied digital video data into a data format conforming to the NTSC (National Television Standards Committee) system or the PAL (Phase Alternation by Line) system. D / A conversion is performed. As a result, an analog video data output by the NTSC system or the PAL system is obtained.

The host interface 18 is connected to an external host computer (not shown), and communicates reproduction data and various commands with the host computer.
In this case, the host interface 18 transmits and outputs the reproduction data transferred via the internal bus 33 to the host computer by performing processing such as packetization according to a predetermined format, for example. A command signal such as a read command from the host computer is supplied to the system controller 24 via the host interface 18.

The system controller 18 includes a microcomputer, and appropriately executes a control process according to a required operation to be executed by each unit constituting the playback device 10.
For example, as described above, an access command, a track jump command, or the like is issued to the servo / PLL circuit 15. Further, the operation switching control of the CD / DVD processor 17 and the data communication control with the host computer via the host interface 18 are performed.
In particular, in the case of the embodiment, as will be described later, based on the standard time information received by the standard time reception processing unit 31, processing for correcting the current time information in the clock unit 30 shown in the figure is also performed. .

Further, the system controller 24 is provided with a ROM (Read Only Memory) 27, a RAM (Random Access Memory) 28, and an NV (Non Volatile) -RAM 29 shown in the figure.
The ROM 27 stores various fixed parameters and operation programs necessary for the system controller 24 to perform various control processes.
The RAM 28 is used as a work area by the system controller 24, and is a storage area for various necessary information.
Furthermore, the NV-RAM 29 is a non-volatile memory that retains stored contents even when power supply is stopped, and necessary information is stored by the system controller 24 as appropriate.

A display unit 25 and an operation unit 26 are connected to the system controller 24.
The display unit 25 displays various information to be presented to the user based on the control of the system controller 24. For example, the operation status, mode status, character data such as the name of music, track (chapter) number, reproduction time information, and other information are displayed. Moreover, the present time information time-measured by the time measuring part 30 mentioned later is also displayed.
The operation unit 26 includes various operation buttons, operation keys, and the like as various operators for user operations. The user gives a required operation instruction to the playback apparatus 10 by operating the operation unit 26. The system controller 24 performs a predetermined control process based on the operation information input by the operation unit 26.

The playback device 10 according to the present embodiment is provided with a clock unit 30, a standard time reception processing unit 31, and a network interface (I / F) 32 shown in the figure.
The time counting unit 30 is a so-called built-in clock or real-time clock that can be operated by a standby power supplied from a secondary battery or the like while the playback device 10 is powered off. Information on the current time counted by the time counting unit 30 is supplied to the system controller 24.
In this case, the time counting unit 30 measures the current time information by year / month / day / hour / minute / second, for example.
The current time information generated by the time counting unit 30 can be corrected by the control of the system controller 24.

  The network interface 32 is an interface for performing data communication with an external device connected via the network 70 shown in FIG. In particular, in the case of the present embodiment, an operation for data communication with the NTP server 80 shown in FIG. 1 is performed based on the control of the standard time reception processing unit 31 described below. .

The standard time reception processing unit 31 controls the network interface 32 to receive standard time information generated by the NTP server 80 connected via the network 70. The standard time reception processing unit 31 is set with designation information for designating a predetermined external device such as the IP address of the NTP server 80 on the network 70. Then, by controlling the network interface 31 based on this designation information, the standard time information from the NTP server 80 is received.
The standard time reception processing unit 31 performs a reception operation at a predetermined time interval set in advance. Note that the reception operation in this case is also controlled by the system controller 24.
The standard time information received by the standard time reception processing unit 31 is supplied to the system controller 24.

3 exemplifies the case where the standard time reception processing unit 31 is configured by hardware, the function of the standard time reception processing unit 31 can also be realized by software processing by the system controller 24.

4). First embodiment

FIG. 4 is a schematic diagram for explaining the operation as the first embodiment of the present invention to be realized by the configuration of the reproduction time management system 1 as the embodiment described so far.
First, as the operation by the reproduction time management system 1 of the first embodiment, as shown as (1) in the figure, the reproduction permission time as additional data to be recorded with the content data on the disc 100 in the recording device 50 is shown. Record the data.

As the reproduction permission time data, for example, information as shown in FIG. 5 is recorded.
As shown in the figure, as the reproduction permission time data, information on a reproduction permission start time and a reproduction permission end time for setting a time range in which reproduction of the content data recorded on at least the disc 100 is permitted is recorded. It is supposed to be.
Alternatively, as indicated by a broken line in the figure, information on a reproduction non-permitted start time and a reproduction non-permitted end time for setting a time range in which reproduction is not permitted may be recorded.
In this case, in addition to the information of the reproduction permission start or end time, the recording time information and the reproduction permission time error information shown in the figure are also recorded.
As the recording time information, the time information when the content data and the reproduction permission time data are recorded on the disc 100 may be recorded.
The reproduction permission time error information is information for setting an allowable range as an error occurring in the current time information timed on the reproduction apparatus 10 side as will be described later. That is, for example, ± 10 seconds is set in the figure. This is because, for example, when the error estimated in the current time information on the playback device 10 side is ± 10 seconds or more, for example, an allowable range is set. This is information for disallowing the reproduction of the content because an excess error has occurred. In other words, in the case where the estimated error is ± 10 seconds or less, for example, it is determined that the error is within an allowable range, and a determination is made as to whether or not to permit reproduction of content data based on the current time information. Information.

  Such reproduction permission time data is input from the additional data input unit 51 in the recording device 50 and is recorded on the master disc 99 by the mastering unit 54 via the data formatter 53, so that the preset time on the disc 100 is preset. The recorded area is recorded.

Returning to FIG. 4, while the recording device 50 records the reproduction permission time data together with the content data on the disc 100 as the operation of (1), on the reproduction device 10 side, as shown in FIG. An operation for matching is performed.
That is, the standard time reception processing unit 31 is configured to receive standard time information every predetermined time as described above. Then, based on the standard time information received by the standard time reception processing unit 31 as described above, an operation for adjusting the current time measured by the time counting unit 30 is performed.
Further, in the playback apparatus 10, the standard time information is received by the standard time reception processing unit 31 in this way, and when time adjustment is performed, as shown in (3), before the update with respect to the standard time (before the standard time adjustment). The error of the current time is calculated. That is, based on the error calculated in this way, as described later, information on an error estimated to occur in the current time information is obtained.
Note that the operations (2) and (3) are operations that are regularly performed by the playback device 10 side.

  When the operations (2) and (3) are performed, the reproducing apparatus 10 first responds to the loading of the disc 100 recorded by the operation (1) described above. As shown in the operation (4), the reproduction permission time data is read from the disc 100.

When the reproduction permission time data is read from the disc 100 as described above, standard time information is received as shown in (5). That is, the standard time reception processing unit 31 receives standard time information from the NTP server 80 based on the control of the system controller 24.
Here, although not shown, when the standard time information can be normally received, an operation for adjusting the current time information of the time counting unit 30 to the standard time is performed based on this. Then, based on the result of comparing the current time information adjusted in accordance with the standard time and the time range information indicated by the reproduction permission time data read out as described above, permission / inhibition of reproduction of the content data is performed. Judgment on permission is made.

On the other hand, when the standard time information cannot be received during the reproduction of the disc 100 as described above, the reproduction of the content data is not immediately permitted in this example, but the following (6) to (9) are not permitted. A determination process / comparison process is performed to determine whether or not to permit reproduction of the content data.
First, in (6), it is determined whether or not the standard time is received. That is, it is determined whether or not the standard time has been received by the standard time reception processing unit 31 in the past in the playback apparatus 10. As a result, if it is determined that the standard time has not been received, for example, a process for disallowing the reproduction of the content data is executed, for example, the reproduction of the content data is not performed. In other words, the current time information in this case is not adjusted to the standard time and is inaccurate, so that the reproduction of the content data is not permitted, and the reproduction permission / non-permission based on the incorrect current time information is determined. Make sure you don't break.

As the operation (7), it is determined whether or not the current time information is manually corrected. That is, when the user's manual correction is performed, the current time information may be an inaccurate value that deviates from the standard time. Therefore, for example, content data is not reproduced. In this way, the reproduction permission / denial determination based on inaccurate current time information is not performed.
Even when such a manual correction is made, the current time information is corrected to a value that is correct when the time adjustment associated with the standard time reception is performed after the correction. it is conceivable that. For this reason, as the operation of (7), it is determined whether or not manual correction is performed after reception of standard time (after adjustment of standard time).

Then, in (8), the estimation error of the current time information based on the elapsed time from the standard time reception is determined.
In realizing the operation (8), first, a time error per unit time due to the time measuring operation of the time measuring unit 30 is obtained. Such a timing error is obtained, for example, based on information on an error between the value of the current time information and the value of the standard time information at the time of reception of the last (last) standard time, which is calculated by the operation (3). be able to. That is, by dividing the error value by the time until this error occurs, the time measurement error per unit time can be obtained. Specifically, according to the value of the elapsed time from the previous standard time reception time (that is, the previous standard time reception time) from the previous standard time reception to the previous standard time reception time, The error value of the current time information may be divided.
Then, after obtaining the timing error in the time counting unit 30 in this way, the elapsed time from the previous standard time reception time to the present is obtained. By multiplying these time measurement errors by the elapsed time up to the present time, it is possible to obtain an error in estimation of the current time information that would have occurred according to the elapsed time from the reception of the previous standard time information to the current time.

When the estimation error that occurs in the current time information is more than necessary, the value of the current time information can be regarded as inaccurate. Accordingly, even when the value of the estimation error of the current time information is more than necessary, it is assumed that the content data is not reproduced, and reproduction permission / non-permission based on inaccurate current time information is performed. Avoid making judgments.
On the other hand, if the error is less than required, the current time information can be assumed to be relatively accurate. In response to this, even when the standard time cannot be received at the time of playback of the disc 100, the determination as to whether or not to permit playback of the content data is made based on the current time information. And
At this time, if it is assumed that playback is immediately disallowed according to the fact that standard time could not be received, even if the current time information is actually correct in this way, The reproduction of the content data is immediately disallowed. Assuming that the current time information that is actually correct in this way is originally within the time range indicated by the reproduction permission time data, the reproduction of the content data should be permitted. Nevertheless, reproduction of the content data is not permitted. That is, there is a possibility that correct reproduction time management is not performed at this point.
In order to prevent such a situation, in this example, even when the standard time cannot be received during playback of the disc 100, if the current time information is accurate, a determination is made as to whether or not playback is permitted. Thus, the reproduction of content data can be permitted even when the current time is originally within the reproduction time range. As a result, more accurate reproduction time management can be performed.

Here, specifically, the operation (8) includes the estimated error value obtained as will be described later and the reproduction permission time data read from the disc 100 by the operation (4). The reproduction permission time error value shown in FIG. 5 is compared, and it is determined whether or not the estimated error value is equal to or greater than the reproduction permission time error value.
That is, in this case, on the premise that the recording device 50 side (for example, the content data seller / copyright holder) compares the estimated error with the reproduction permission time error on the reproduction device 10 side. By recording the information of the reproduction permission time error with respect to 100, the current time counted by the reproduction device 10 is set to the current time according to the case where the current value is within the allowable error range. Based on this, it is possible to determine whether to permit or not permit reproduction.
In other words, for example, when the current time information is expected to be an inaccurate value because a relatively long time has passed since the reception of the standard time, the reproduction permission / denial determination is not performed. In addition, the reproduction of the content data can be prohibited.

Further, as the operation (9), the current time and the reproduction permission time data are compared. That is, it is determined whether or not the value of the current time information is within the reproduction permission time range indicated by the reproduction permission start time and the reproduction permission end time in the reproduction permission time data read from the disc 100.
As understood from the above description, the operation of (9) in the case of this embodiment is not only when the standard time is received in (5) above, but also when the standard time is not received in (5). Even in the case of (6), (7), and (8), the standard time has been received in the past, and the current time information is not manually corrected and the error is determined to be less than required. Become.
As the operation (9), for example, when the current time is not within the reproduction permission time range, the operation for disabling the reproduction of the content data is performed, such as the reproduction of the content data is not performed. Like that. On the other hand, when it is determined that it is within the reproduction permission time range, the content data is reproduced.

  By the way, when performing the operation described with reference to FIG. 4, for example, in order to determine the presence / absence of standard time reception (6), information on the presence / absence of such standard time reception is stored on the playback device 10 side. Need to be. Also, when determining whether or not (7) is corrected or obtaining the estimation error of (8), various necessary information needs to be stored.

In the reproducing apparatus 10 according to the embodiment, for example, various kinds of information as shown in the following FIG. 6 are stored as the necessary information.
First, as shown in FIG. 6, the “time at the time of reception of the previous standard time” is stored. This is to store time information based on the standard time information when the standard time reception processing unit 31 receives the standard time information in the standard time adjustment operation of FIG. In addition, “the time when the second standard time is received” is also stored.
Further, as the “time clock part error at reception” shown in the figure, the error value calculated by the operation of FIG. 4 (3) is stored.
Further, as “presence / absence of correction”, information on the presence / absence of manual correction with respect to the current time information is stored.

Here, the above-mentioned “time at the previous standard time reception” is updated every time the standard time reception processing unit 31 receives the standard time information. By leaving the value without erasing it, it is possible to store this value as the “time at the time of reception of the previous standard time”.
In addition, as for the information of “presence / absence of correction”, for example, a value corresponding to “Yes” is written in response to manual correction of the current time, and standard time information is received and standard time adjustment is performed. In response to this, a value of “none” is written. By doing in this way, only when manual correction is performed after the standard time adjustment, the “presence / absence of correction” item can be set to “present”, and as a result, after the standard time adjustment as described above, Only the presence or absence of correction can be determined.
6 may be stored in, for example, the NV-RAM 29 shown in FIG. 3 or the like, which is necessary for realizing the operation as the embodiment shown in FIG.

The processing operation to be executed by the system controller 24 shown in FIG. 3 when realizing the operation as the first embodiment according to the above description will be described with reference to the flowcharts of FIGS.
In these drawings, FIG. 7 shows the processing operation that the system controller 24 regularly performs to realize the operation as the embodiment, and in FIG. 8, the disc 100 is loaded into the playback apparatus 10. Corresponding to the case, the processing operation executed by the system controller 24 is shown.

First, in the flowchart shown in FIG. 7, the system controller 24 performs a determination process as to whether or not the standard time has been received by the process of step S101 shown in the figure.
In step S101, if no standard time information is received by the standard time reception processing unit 31 and a negative result is obtained, the process proceeds to step S106, and whether or not there is a manual input for correcting the current time information. The discrimination process is performed. In step S106, for example, if a predetermined operation is not performed on the operation unit 26 and a negative result is obtained that manual input for such correction of the current time information is not performed, the process proceeds to step S101. Then, the discrimination processing for standard time reception is performed again.
By such a flow of processing from step S101 to step S106, a loop for waiting for either standard time reception or manual input is formed.

If a positive result is obtained in step S106 that the above-described manual input has been performed, the process proceeds to step S107 to perform time adjustment processing. That is, the time is adjusted by correcting the value of the current time information in accordance with the user operation performed in step S106.
Further, in the subsequent step S108, in accordance with the correction of the current time information by manual input in this way, the information on the presence / absence of correction is updated to a value corresponding to “present”, and the process is again performed in step S101. Proceed.

  On the other hand, if a positive result is obtained in step S101 that the standard time information has been received, processing for standard time adjustment is performed in step S102. That is, the standard time information received by the standard time reception processing unit 31 is input, and the value of the current time information measured by the time counting unit 30 is corrected based on the value.

In FIG. 7, when the standard time adjustment process is executed in step S102, in the subsequent step S103, the information on the presence / absence of correction shown in FIG. 6 is updated to a value corresponding to “none”.
In step S104, an error between the current time before the update and the received standard time is calculated.
That is, when the standard time adjustment is performed in the previous step S102, the error of the value of the current time information (current time before update) timed by the time counting unit 30 with respect to the received standard time information value is calculated. To do.

In step S105, a process of storing the received standard time information and the calculated error information is executed.
For example, these standard time information and error information are recorded in the NV-RAM 29 shown in FIG. Then, the standard time information recorded in this way is stored as the “time at the previous standard time reception” shown in FIG.

Note that, in the case of the embodiment, in response to the determination based on the estimation error of the current time information as described above, the time measurement error per unit time in the time counting unit 30 is obtained. Has been. In this embodiment, as described above with reference to FIG. 6, in addition to the above-mentioned “time at the time of reception of the previous standard time” which is the standard time information received immediately before, “2 The information of “the time at the time of reception of the previous standard time” is stored.
For this reason, although illustration is omitted as processing of this step S105, when the received standard time information is the second time or later, it was received one time before it together with the standard time information received in step S101. It is assumed that processing for storing standard time information is performed.
As described above, as such processing, for example, only the standard time information for the past two receptions of the standard time information received so far may be stored.

  As a result of the operation shown in FIG. 7, the playback apparatus 10 side “time at the time of reception of the previous standard time” “reception time” necessary for realizing the operation as the embodiment shown in FIG. Information of “time counter part error”, “time of reception of two previous standard times” and “presence / absence of correction” are stored.

Next, processing operations to be executed by the system controller 24 corresponding to the case where the disc 100 is loaded in the playback apparatus 10 will be described using the flowchart of FIG.
In FIG. 8, it is assumed that the disc 100 is already loaded in the reproducing apparatus 10.
In FIG. 8, first, in step S201, reproduction permission time data reading processing is executed.
In other words, for example, in response to the loading of the disc 100 as described above, the reproduction permission time data is read by causing the predetermined area on the disc 100 to be read out.

In step S202, the standard time is received. That is, the standard time reception processing unit 31 shown in FIG. 3 is controlled to perform a standard time information reception operation.
In step S203, a determination process is performed as to whether the standard time reception is successful.
In step S203, if it is determined that the standard time reception processing unit 31 has received the standard time information based on the control in step S202 and an affirmative result is obtained, the process proceeds to step S208, and the completion of the standard time adjustment is monitored. . That is, the standard time reception processing unit 31 receives the standard time information in this way, and monitors the completion of the standard time adjustment operation (step S102) performed in response to obtaining a positive result in the process of step S101 of FIG. Is.
When the standard time adjustment is completed, the process proceeds to step S209, which will be described later, so as to determine whether or not the current time is within the reproduction permission time range.

On the other hand, if it is determined in step S203 that standard time information could not be received and a negative result was obtained, in step S204, it is determined whether or not standard time information has been received in the past. This determination processing can be performed, for example, based on determination of whether or not the information of “the time at the previous standard time reception” is stored among the information shown in FIG.
In this step S204, for example, when the information of the above “time at the previous standard time reception” is not stored and a negative result is obtained that the standard time information has not been received in the past, a step S211 is obtained. The process is advanced to the reproduction control process.

Here, as the reproduction control process in step S211, a process for preventing reproduction of content data from the loaded disc 100 may be executed.
For example, the operation for preventing the reproduction may be performed immediately by ejecting the loaded disc 100 or the like.
Alternatively, first, a process may be performed other than that which immediately prohibits the reproduction of the content data, such as displaying a message indicating that the standard time information cannot be received on the display unit 25 shown in FIG. Good.

If an affirmative result is obtained in step S204 that standard time information has been received in the past, the process proceeds to step S205, and whether or not the current time information has been manually corrected. The discrimination process is performed. That is, in the information shown in FIG. 6, if a value corresponding to “present” is stored as the “presence / absence of correction” information, the current time information currently measured by the time counting unit 30 is manually set. A positive result is obtained as having been corrected. When a value corresponding to “None” is stored, a negative result is obtained on the assumption that the current time information is not manually corrected.
If an affirmative result is obtained assuming that the current time information has been manually corrected, the process proceeds to step S211 to execute the above-described regeneration control process.
If a negative result is obtained that the current time information is not manually corrected, the process proceeds to step S206.

In step S206, an estimation error is calculated.
In other words, the estimation error information that is expected to be present in the current time information currently measured by the time counting unit 30 is calculated.
For example, as described above, the estimation error is calculated as shown in FIG. 6 by referring to “the error in the timekeeping unit at the time of reception”, “the time at the time of reception of the previous standard time”, and “at the time of reception of the previous standard time”. It can be performed using the information of “time”. That is, the elapsed time at which the above-mentioned “error of the timekeeping part at the time of reception” occurs is obtained from “the time at the time of reception of the previous standard time” and “the time of reception of the previous standard time”. Then, the “error of the timekeeping part at the time of reception” is divided by the elapsed time thus obtained, and the period from “the time when the standard time is received two times before” to “the time when the previous standard time is received” The time measurement error per unit time of the time counting unit 30 is obtained.
On top of that, by multiplying the timing error per unit time of the time counting unit 30 by the value of the elapsed time from the “time at the previous standard time reception” to the present time, the current time counting unit An estimation error of current time information timed at 30 can be calculated.

In the subsequent step S207, it is determined whether or not the estimated error value exceeds the reproduction permission time error value. That is, it is determined whether or not the estimated error value calculated as described above exceeds the value of the reproduction permission time error in the reproduction permission time data read from the disc 100.
If a positive result is obtained that the estimated error value exceeds the reproduction permission time error value, the process proceeds to step S211 to execute the reproduction control process. In other words, this makes it possible to prevent the judgment on whether to permit or not permit reproduction based on the current time information in response to the case where the error of the current time information with respect to the standard time is outside the allowable range.
If a negative result is obtained that the estimated error value does not exceed the reproduction permission time error value, the process proceeds to step S209 to check whether the current time is within the reproduction permission time range. Perform discrimination processing. That is, when the error of the current time information with respect to the standard time is within an allowable range, it is possible to make a determination as to whether or not to permit reproduction based on the current time information.

  In addition, according to the estimation error calculation method in step S206 described above, the time measurement error of the time counting unit 30 is calculated every time standard time information is received. For example, the time measurement error of the time measurement unit 30 is expected. The estimated error may be obtained by multiplying this value by the elapsed time from immediately before to the present. In this way, it is not necessary to memorize the error at the time of standard time reception and to calculate the time error based on this error, thereby reducing the processing burden.

Alternatively, the determination may be made based on only the elapsed time. That is, since the information on the elapsed time from the time at the previous reception of the standard time is also proportional to the error occurring in the current time information, the determination process may be performed. As a result, it is not necessary to calculate an error, so that the processing load can be further reduced.
However, in this case, as a matter of course, the value of the reproduction permission time error in the reproduction permission time data recorded on the disc 100 needs to be set in accordance with such elapsed time as a reference. .

In step S209, it is determined whether or not the current time is within the reproduction permission time range.
That is, first, the reproduction permission time range is recognized from the information of the reproduction permission start time and the reproduction permission end time in the reproduction permission time data read from the disc 100. Then, it is determined whether or not the time according to the current time information counted by the time counting unit 30 is within the recognized reproduction permission time range.
As a result, if a negative result is obtained that the current time is not within the reproduction permission time range, the process proceeds to step S211 to execute the reproduction control process.
If an affirmative result is obtained that the current time is within the reproduction permission time range, the process proceeds to step S210 to execute a process for reproducing content data.

As a result of the processing shown in FIG. 8, in the present embodiment, even when standard time information cannot be received during playback of the disc 100, the standard time is received in the past, and manual correction is performed after the standard time is received. Accordingly, when the estimated error is within the range of the reproduction permission time error recorded on the disc 100, the current time information can be compared with the reproduction permission time range.
In other words, even when the standard time information cannot be received when the disc 100 is played back, if it is determined that the current time information is accurately measured, permission to play back the content data based on the current time information is given. / It will be possible to make a non-permission decision.

  In this way, in the reproduction time management system 1 of the present embodiment, the recording apparatus 50 records the reproduction permission time data for permitting / denying reproduction of the content data on the disk 100, and the reproduction apparatus 10 uses the disk Since the reproduction of the content data is controlled based on the result of comparing the content of the reproduction permission time data read from 100 and the current time information measured by itself, the recording device 50 side (for example, sales of the disc 100) is controlled. In other words, a mechanism that allows the reproduction of the content data on the reproduction apparatus 10 side (for example, the user of the reproduction apparatus 10) is realized only within a time range designated by the user or the copyright holder.

  In addition, since the standard time information is received from the predetermined NTP server 80 as the standard time information, accurate reproduction time management based on the predetermined standard time information designated on the recording device 50 side is realized. be able to. If accurate management can be performed in this way, a stronger copyright protection function can be obtained as the reproduction time management system 1 accordingly.

Further, in the present embodiment, even when the standard time information cannot be received when the disc 100 is played back, the standard time is received in the past, and no manual correction is performed after the standard time is received, and the estimation error is recorded on the disc 100. When it is determined that the current time information is accurate, such as when the reproduction permission time error is within the range, a determination is made as to whether or not to permit reproduction of the content data based on the current time information. .
According to this, for example, the current time information is an accurate value within the reproduction permission time range and is not within the reproduction permission time range. Is prevented, and in this respect, more accurate reproduction time management can be realized.

Further, as can be seen from the operation shown in FIG. 8, in the reproduction time management system 1 of the present embodiment, the current time information counted by the reproduction apparatus 10 is a predetermined standard time when the disk 100 is reproduced. Even if it is not possible to receive the standard time, the content data cannot be reproduced unless it is timed with an accurate value and within the permitted reproduction time range as described above. It can be.
That is, according to the reproduction time management system 1 as described above, as a user of the reproduction apparatus 10, the current time information is at least a predetermined content intended by the copyright holder or seller (recording apparatus 50 side) of the content data. Copyright holders and playback device users that can be played back properly if it is within the error range and within the permitted playback time range, but cannot be played if the error range or playback permitted time range is exceeded. It is possible to control more accurate reproduction of content data in accordance with the contract conditions between

  In the first embodiment, the standard time information received immediately before and immediately before is stored, and the estimation error of the current time is calculated based on the time information and error information of only one section before. However, instead of this, the time information at the time of the standard time reception of the past several times, the time counter 30 at that time and the error of the standard time are stored, and based on the time information and error information in these multiple sections The estimation error may be calculated. In this way, the value of the current time including the estimation error can be estimated more accurately.

This will be described with reference to FIGS. 9 to 10 below.
First, as such a method, as shown in FIG. 9A, time information at the time of standard time reception and error information at that time are respectively expressed as “time history at reception”, “error history at reception”. ”For the past several times.
Then, from the history information stored in this way, as shown in FIG. 9B, information on the number of days between the histories, and information on the timing error per day between the histories, for example, Get.

  For example, according to the example in the figure, it can be seen that the error per day between the past several histories has a maximum value of 0.389 seconds in the histories 3 to 4. And, for example, if the maximum value of errors between the past several histories is set as the time measurement error per unit time in the time counting unit 30, the error between the previous histories happens to be small. In this case, the current time can be estimated more accurately without being influenced by this value.

Alternatively, the timing error may be determined using a statistical estimation method from a group of error values per day based on the past history.
Based on the previous example of FIG. 9, the error between each history, the number of days between standard time reception, and the transition of the error per day are shown in a graph in FIG. On the assumption that the error value group per day based on the history is a sample group from a population based on a normal distribution, for example, the time error value per day based on an appropriate confidence interval is estimated.
If the time measurement error per unit time is determined using the statistical estimation method in this way, a more reliable time error value can be estimated from the past history. Can be estimated more accurately.

In the present embodiment, it is desirable to adjust the standard time reception interval in the standard time reception processing unit 31 based on the value of the time error of the standard time reception time in the past calculated as described above. For example, if standard time information has been received at intervals of 24 hours so far, if the timekeeping error per day is calculated as 2 seconds, the information should be received at intervals of 6 hours, for example, to reduce the error. By adjusting, the error per day can be reduced to, for example, about 0.5 seconds. Also, for example, when standard time information is received at 24 hour intervals, if the error per day is calculated as 0.1 seconds, for the purpose of prioritizing power saving over time accuracy, For example, the number of receptions is decreased and changed to, for example, a 48-hour interval.
The reception interval in the standard time reception processing unit 31 can be changed under the control of the system controller 24.

5). Second embodiment

Here, according to the description of the first embodiment, the playback apparatus 10 sets predetermined specification information for specifying the NTP server 80 for the standard time reception processing failure 31 so that a predetermined external number is set. It was supposed to receive standard time information generated by the device, but in the unlikely event that this designation information is changed to information that designates a different server, the recording device 50 cannot be adjusted to the intended standard time End up.
Therefore, in the second embodiment, it is assumed that designation information for designating a predetermined NTP server 80 is also recorded on the disc 100, and the playback apparatus 10 side receives from the predetermined NTP server 80 based on this designation information. The standard time information is received so that more accurate reproduction time management can be performed based on a predetermined standard time.

For this reason, in the second embodiment, the designated server information is recorded on the disc 100 together with the reproduction permission time data as shown in FIG. In other words, such designated server information is input via the additional data input unit 51 shown in FIG. So that
For example, the reproduction permission time data and the designated server information are recorded in a predetermined area on the disc 100 as reproduction permission time recording data as illustrated.
In this case, as the designated server information, for example, information on the IP address of the NTP server 80 to be designated may be recorded. Alternatively, information of the domain name or host name (so-called fully qualified domain name (FQDN)) may be recorded.

  On the other hand, the playback device 10 receives standard time information when playing back the content data from the disc 100 on which the playback permission time recording data based on the playback permission time data and the specified server information is recorded. First, the designated server information reproduced from the disc 100 is recognized. Then, the standard time information from the NTP server 80 designated by the designated server information is received.

The processing operation for realizing the operation as the second embodiment is shown in the flowchart of FIG.
First, the system controller 24 reads the reproduction permission time recording data from the disc 100 by the process of step S301 shown in the figure.
In step S302, the designated server information in the reproduction permission time recording data is recognized. That is, the designated server information in the reproduction permission time recording data shown in FIG. 11 is recognized.

Then, in the subsequent step S303, the standard time reception processing unit 31 receives standard time information. That is, in this case, as the processing in step S303, the designated server information recognized as described above is set in the standard time reception processing unit 31, and the standard time information from the NTP server 80 designated by the designated server information is received. It is what you want to do.
Thereafter, the same processing operation as that after step S203 described with reference to FIG. 8 is performed.

As a result of such processing, in the second embodiment, standard time information of the NTP server 80 specified by the specified server information recorded on the disc 100 on the recording device 50 side is displayed on the playback device 10 side. It can be surely received. According to this, for example, the user of the playback device 10 installs an NTP server that does not coincide with the standard time, thereby making it difficult for the player to impersonate the playback device 10 as if it is synchronized with the standard time. Thus, the current time information measured on the playback device 10 side can be more reliably synchronized with predetermined standard time information.
That is, more accurate reproduction time management can be realized by this.

Here, according to the operation shown in FIG. 13, when the standard time information cannot be received when the disc 100 is played back, it is not questioned whether the current time information is synchronized with the standard time by the designated NTP server 80. However, when the standard time cannot be received at the time of reproduction as described above, various determination processes (steps S305 to S308) regarding the reliability of the current time information are executed. It can be said that there is sex.
For this reason, in this case, in response to the case where the standard time information cannot be received, it does not matter whether it is synchronized with the standard time information by the designated NTP server 80. If there is a possibility that the content data is synchronized with the content data, it may be considered illegal and the reproduction of the content data may be prohibited.

  In the case of corresponding to this, for example, as a process after the process of determining whether or not the standard time reception is successful (S304) shown in FIG. 13, the NTP server which is the transmission destination of the standard time information received immediately before is shown. For example, a process for determining whether the IP address information matches the IP address information based on the designated server information reproduced from the disk 100 is provided. Then, if these pieces of information match, the subsequent processing is executed, and if they do not match, reproduction may be disallowed.

However, in order to realize such an operation, it is necessary to store the information of the NTP server that received the standard time in the past. For this purpose, for example, as shown in FIG. 14, the routine processing operation performed on the playback apparatus 10 side shown in FIG. 7 is changed.
That is, processing for acquiring the receiving server information is performed as the next step S402 in response to the reception of the standard time in step S401 shown in the figure. In other words, the standard time reception processing unit 31 acquires information on, for example, the IP address of the NTP server connected for the current standard time reception. In the subsequent steps S403 to S405, the same processing as that in steps S102 to S104 shown in FIG. Processing to store information is performed.
As a result, as shown in FIG. 12, the information stored on the playback device 10 side can store the receiving server information as described above in addition to the information shown in FIG. .

In the second embodiment, the following operation can be performed instead of the operation shown in FIG.
First, it is assumed that the recording device 50 side records the reproduction permission time recording data including the designated server information on the disc 100 in the same manner.
Then, on the reproducing apparatus 10 side, when reproducing the reproduction permission time recording data from the disc 100, for example, a message indicating that the information of the NTP server 80 designated by the designated server information is set in the standard time reception processing unit 31 is displayed. The user is notified via the unit 25 or the like.
Then, in response to the standard time reception during reproduction of the disc 100, the designated server information is compared with the information (for example, IP address) of the NTP server that is the transmission destination of the received standard time information. As a result of this comparison, if the pieces of information do not match, reproduction is not permitted.
Even in this way, if the standard time reception from the designated NTP server 80 is not performed, reproduction can be prohibited, so that for example, falsification of current time information using an unauthorized NTP server is prevented. Thus, more accurate reproduction time management becomes possible.

In the second embodiment, when the standard time information is received, the time may not be adjusted by one designated NTP server 80 in some cases.
Thus, for example, history information about the receiving server is recorded at the time of standard time reception in the past, and if connection to the NTP server 80 designated at the time of reproduction of the disk 100 is not established, such history is included in the history. Whether or not the information of the designated NTP server 80 is included is searched. At this time, if the information of the specified NTP server 80 is included in the history, and the standard time received in the subsequent history is not changed more than the statistically estimated error, the specified The NTP server 80 can be synchronized with the standard time. That is, the received standard time information may be regarded as standard time information by the designated NTP server 80 and the subsequent processing may be executed.
On the contrary, when the information of the specified NTP server 80 is not included in the history, or even if it is included, the standard time received in the subsequent history is changed beyond the statistically estimated error Can be considered to be illegal standard time information, for example, reproduction of content data can be prohibited.

6). Third embodiment

In this way, according to the first and second embodiments described above, the reproduction time range is compared while the current time information is accurately measured on the reproduction apparatus 10 side, for example, The seller side and the user side can use it according to the contract conditions.
However, on the other hand, if the reproduction permission time data recorded on the disk 100 side is falsified, the current time information on the reproduction apparatus 10 side is accurate even if the current time information is accurately counted. Use is impossible.

Therefore, in the third embodiment, the reproduction permission time data for determining the reproduction permission time of the content data is encrypted and recorded on the disc 100 in order to prevent such falsification.
For example, if the playback permission time data is recorded in plain text without being encrypted, and the playback apparatus 10 is configured to read such plain text playback permission time data as it is, as described above. Malicious copyright infringers who perform pirated manufacturing activities, etc. can easily create pirated discs with altered playback permission start time and playback permission end time information (that is, playback permission time range information) in the playback permission time data. Can be played back by the playback device 10.
For this reason, the reproduction permission time data is encrypted and recorded, and the reproduction apparatus 10 decrypts the data, thereby preventing the manufacture and distribution of pirated discs.

First, when realizing such an operation as the third embodiment, an encryption processing unit 55 is added as shown in FIG.
Data necessary for the encryption process is input to the encryption processing unit 55 as the illustrated data input. That is, in this case, encryption key data necessary for encrypting the reproduction permission time data is input.
Then, the encryption processing unit 55 performs an encryption process on the reproduction permission time data input to the data formatter 53 via the additional data input unit 51 based on the input encryption key data. The
Note that the configuration of the playback apparatus 10 in this case is substantially the same as that of the first embodiment, and therefore, the description by illustration is omitted here.

FIG. 16 is a schematic diagram for explaining operations performed in the reproduction time management system 1 as the third embodiment.
First, in the reproduction time management system 1 according to the third embodiment, a set of a secret key and a public key is generated in advance by the asymmetric encryption method as the operation (1) shown in the figure before the disc 100 is manufactured. Shall.
In this case, the secret key is used to encrypt the original plaintext data at the time of recording, and the paired public key decrypts the encrypted data into plaintext data at the time of playback on the playback device 10 side. It is used for this purpose. Specific examples of asymmetric cryptosystems used here include RSA cryptosystems classified as prime factorization (IF), ElGamal cryptosystems classified as discrete logarithmic (DL), and elliptic curve (EC) An elliptic curve cryptosystem classified as follows, that is, an encryption system as defined in the IEEE 1363 standard can be used.

The secret key data generated by the asymmetric encryption method in this way is input to the encryption processing unit 55 in the recording apparatus 50 as the data input shown in FIG. Alternatively, such secret key data may be stored in the recording device 50 in advance.
Further, the public key data is held on the playback device 10 side. The public key data may be stored in the ROM 27 shown in FIG. 3, for example.

In this way, after assigning the secret key to the recording device 50 side and the public key to the reproducing device 10 side, first, on the recording device 50 side, reproduction permission time data as shown as (2) in the figure. Header data based on a part of the data is generated.
Then, as the subsequent operation (3), the reproduction permission time data by the secret key and the specified server information described in the second embodiment are encrypted. Then, as the operation of (4), the encrypted reproduction permission time data and designated server information and the header data generated in (2) are recorded on the disc 100 as reproduction permission time recording data. .

Here, as the header data as described above, for example, as shown in the following FIG. 17, as the items in the reproduction permission time data, for example, data using the first two items of data is generated as it is. In this case, as shown in the figure, data of “recording time” and “manufacturing factory symbol” which are the first two items in the reproduction permission time data are used.
The reproduction permission time data of the third embodiment shown in this figure includes the recording time, the reproduction permission start time, and the reproduction permission end time that were recorded in the first and second embodiments. In addition to the reproduction permission time error, the above-mentioned manufacturing factory symbol item is added, but this is not particularly essential.
In addition, as the header data, the first two items in the reproduction permission time data are set to be used here, but this item is not particularly limited. And the number thereof may be set.
Alternatively, the designated server information may be included.

As such header data, the encryption processing unit 55 extracts from the reproduction permission time data in the plain text state input to the data formatter 53 via the additional data input unit 51 shown in FIG. Is generated. That is, the header data in this case is plain text data. Here, such plain text header data is assumed to be header data R1a as shown in FIG.
On the other hand, the reproduction permission time data itself is encrypted by the encryption processing unit 55 based on the input secret key as the operation of FIG. The reproduction permission time data thus encrypted with the secret key is set as reproduction permission time data R1b as shown in FIG. Similarly, the designated server information is encrypted based on the input secret key by the encryption processing unit 55. The designated server information thus encrypted is designated server information R1c. .

Then, depending on the operation of FIG. 16 (4), the encrypted reproduction permission time data R1b and the designated server information R1c and the plaintext header data R1a are combined with the reproduction permission time recording data R1 (in FIG. 17). As shown in FIG.
That is, the encryption processing unit 55 supplies the reproduction permission time data R1b and the designated server information R1c subjected to the encryption processing and the header data R1a generated previously to the data formatter 53 as the reproduction permission time recording data R1. In response to this, the data formatter 53 performs a predetermined formatting process, and the mastering unit 54 performs the mastering based on the format processing. Reproduction permission time recording data R1 is recorded.
As a result of such an operation, in the third embodiment, plain text header data R1a, encrypted reproduction permission time data R1b, and designation are designated in a predetermined area on the disk 100 as shown in FIG. The reproduction permission time recording data R1 based on the server information R1c is recorded.

Next, the operation performed on the reproducing apparatus 10 side in response to the case where the disc 100 on which the reproduction permission time recording data R1 is recorded in this way is described with reference to the schematic diagram of FIG. To do.
First, the playback device 10 in this case holds a public key generated by an asymmetric encryption method using, for example, the ROM 27 as described above. That is, the public key that is paired with the secret key used for encrypting the reproduction permission time data on the recording device 50 side is held in advance.
For example, when the disc 100 is loaded, the reproduction permission time recording data R1 is read from a predetermined area on the disc 100 as shown in the operation (1).

  In the subsequent operation (2), the reproduction permission time data R1b and the designated server information R1c encrypted with the secret key in the reproduction permission time recording data R1 read out in this way are used using a public key stored in advance. To decrypt. That is, by storing the public key that is paired with the secret key generated by the asymmetric encryption method in advance as described above, the reproduction permission time data R1b and the designated server information R1c can be appropriately decrypted. It is.

  When the reproduction permission time data R1b and the designated server information R1c are decoded in this way, the operation (3) corresponds to the header data in the reproduction permission time recording data R1 and the header data of the decoded reproduction permission time data. Compare the matching parts. In other words, according to the previous example, in this case, the recording time / manufacturing factory symbol data as header data coincides with the recording time / manufacturing factory symbol data in the reproduction permission time data obtained by decoding. Are compared.

Here, as a result of such comparison processing, if the two data match, it can be proved that the encrypted reproduction permission time data is encrypted by the paired secret key. That is, the fact that the data encrypted with the paired secret key could be correctly decrypted with the paired public key assigned in advance to the playback apparatus 10 side means that the playback permission read from the disc 100 is read. The time data R1b is a proof that the regular recording device 50 side has encrypted it with the correct private key to be paired.
Conversely, if the two data do not match, the reproduction permission time data R1b recorded on the disc 100 is not encrypted (recorded) with the correct private key paired with the proper recording device 50. For example, it can be illegal data encrypted by an illegal secret key or the like with an incorrect secret key.
In this way, under encryption / decryption using an asymmetric encryption key (secret key, public key), the contents of the header data R1a in plain text before encryption and the contents of the header data R1a after decryption are matched. By comparing these, it is possible to determine whether the recorded reproduction permission time data is correct. That is, it is possible to determine whether or not the reproduction permission time data recorded on the disc 100 has a possibility of falsification.

If a match is found as a result of such comparison, the standard time information based on the designated server information is received and an operation corresponding to the result is performed as shown in (4).
That is, in response to the case where the reproduction permission time data recorded on the disc 100 is normally recorded as described above, the standard time information based on the designated server information described in the second embodiment. The operation after the reception is performed.
If no match is found, reproduction of the content data is not permitted. As a result, for example, the reproduction of the content data of the disc 100 on which the reproduction permission time data, which is encrypted with an illegal secret key by an illegal trader or the like and is likely to be falsified, is not permitted. it can.

The processing operation to be executed by the system controller 24 of the playback apparatus 10 for realizing the operation as the third embodiment according to the above description will be described with reference to the flowchart of FIG.
In FIG. 19, only the operation corresponding to the time when the disc 100 is loaded is shown as the operation performed by the reproducing apparatus 10, and as the steady operation other than the time when the disc 100 is loaded, the case of the third embodiment is also shown in the previous figure. 7 is the same as that shown in FIG.

In FIG. 19, the system controller 24 in this case first executes a process of reading the reproduction permission time recording data R1 from the loaded disk 100 by the process of step S501 shown in the figure.
In step S502, the encrypted data in the reproduction permission time recording data R1 is decrypted using a public key stored in advance. That is, the reproduction permission time data R1b and the designated server information R1c are decrypted.

  In step S503, a portion corresponding to the header data R1a in the decoded reproduction permission time data is recognized. That is, based on the content of the header data in the reproduction permission time recording data R1 read out in step S501, a portion corresponding to the header data R1a in the reproduction permission time data after decoding is recognized.

In the following step S504, the match between the header data R1a and the portion corresponding to the recognized header data is compared. That is, the data content of the portion corresponding to the recognized header data R1a is compared with the data content of the header data R1a.
In step S505, a determination process is performed as to whether or not the data contents match from the result of the comparison. If a negative result is obtained because the data contents do not match, the process proceeds to step S312 shown in FIG. 13 and the reproduction control process is executed. That is, the content data is not reproduced in response to the case where the decrypted data does not match the data content before the decryption and the recorded reproduction permission time data may be falsified. Can be.
If a positive result is obtained in step S505 that the data contents match, the process proceeds to step S302 shown in FIG. 13 to recognize the specified server information and receive standard time information. The operation according to the result is performed.

Thus, according to the reproduction time management system 1 of the third embodiment, the reproduction permission time data is encrypted with the secret key and recorded on the disc 100. The reproduction permission time data encrypted in this way can be decrypted only in the reproduction apparatus 10 in which the public key to be paired is stored.
In other words, the playback apparatus 10 correctly decrypts the playback permission time data encrypted with the regular private key on the disc 100 and permits / disables playback of the content data thereafter. Can be processed for.
That is, according to such a system, unless the encryption key on the recording device 50 side is illegally taken out, for example, a third party such as an illegal trader can decrypt the playback device 10 side with the correct encryption key. It becomes difficult to manufacture the regular disc 100, and thus, for example, it is difficult to manufacture the disc 100 in which the content of the reproduction permission time data has been tampered with.
Further, by preventing falsification of the content of the reproduction permission time data recorded on the disc 100, more accurate content reproduction time management can be performed, and thus a stronger copyright protection function can be realized. .

  Further, as the third embodiment, since the operations as the first and second embodiments are also performed, it is possible to prevent the reproduction permission time data from being falsified, By realizing more accurate playback time management when the time information is accurately timed, the copyright protection function from both sides can be strengthened.

Further, in the third embodiment, as described above, a part of the plaintext of the reproduction permission time data is recorded on the disc 100 as the header data R1a (reproduction permission time recording data R1). On the playback device 10 side, the playback permission time data R1b recorded in this way is decrypted with the public key, and the contents corresponding to the header data R1a and the decrypted header data R1a are compared. To do.
By making such a comparison, when these data contents match, the reproduction permission time data R1b is paired with the public key that can decrypt the reproduction permission time data R1b on the reproduction apparatus 10 side. It can be proved that it is encrypted with the private key. That is, the reproduction permission time data can be proved to be recorded by the regular recording device 50.

Note that although the secret key data is input from the outside to the recording device 50 shown in FIG. 15, it is stored in advance in a required internal storage medium as in the case of the playback device 10. You may leave it.
The designated server information may be recorded as plain text without being encrypted.

7). Fourth embodiment

As described above, after performing encryption with a secret key of an asymmetric cryptosystem and decryption with a public key, by comparing the match between the header data before encryption and the header data after decryption, It can be proved that the data recorded on the disk 100 is recorded by the regular recording device 50.
However, if only one set is used as the asymmetric encryption key used for encryption / decryption of the reproduction permission time data as in the third embodiment, the only secret key is illegal. When taken out by various means, there is a possibility that the disc 100 as if recorded by the regular recording device 50 could be forged using this secret key.

  Alternatively, even if the secret key is not taken out to the outside, when the key length of the asymmetric encryption key is not sufficient, the public key on the playback device 10 side, a series of plaintext data as the header data R1a, and encryption It cannot be said that there is no possibility that the paired secret key is discovered using the reproduction permission time data R1b.

Therefore, in the fourth embodiment, a plurality of pairs of secret keys and public keys that are paired by the asymmetric encryption method are generated, and the reproduction permission time data is generated by any one of them. It is assumed that encryption / decryption is performed.
If a plurality of sets of asymmetric encryption keys are prepared in this way and only one required set is selected and used, which public key is selected and used for decryption on the playback device side. In other words, it is difficult to grasp which secret key is selected and used on the recording side, and therefore it is necessary to specify the secret key using the public key, header data R1a, and reproduction permission time data R1b as described above. , That can be difficult.
Alternatively, when a secret key is taken out on the recording apparatus 50 side, similarly, which key is correspondingly selected and used for decryption on the reproducing apparatus 10 side, that is, a pair is formed on the recording apparatus 50 side. It is difficult to know which secret key is used, and it is difficult to specify the secret key.
Since the identification of the secret key can be made difficult in this way, as a so-called impersonation act, in this case, for example, it is possible to prevent the counterfeit disc 100 from being manufactured by the secret key that has been taken out or estimated. Can be planned.

However, when a plurality of keys are used in this way, it is necessary to be able to correctly select which set of keys to use on the recording device 50 side and the playback device 10 side by some mechanism. The operation of the fourth embodiment including such a mechanism is as shown in FIG.
First, in FIG. 20, as (1) shown in the figure, a plurality of sets of secret keys and public keys are generated by an asymmetric encryption method. Similarly, in this case, these secret keys are used for encrypting plaintext data as reproduction permission time data at the time of recording, and the public keys to be paired with each other are the reproduction permission time data encrypted at the time of reproduction as plaintext data. It is used for decryption.

In addition, in the fourth embodiment, as (2), setting of data section information and a predetermined hash function is performed.
The data section is information for designating a partial section of data to be recorded on the disc 100 on the recording device 50 side, for example, and an arbitrary plaintext data section is determined in advance. For example, a partial section of header data in the reproduction permission time data may be set, or a partial section of content data may be set.
Then, a plurality of secret keys generated and set by (1) and (2) and data section / hash function information are input to the recording device 50. That is, to the recording apparatus 50 in this case, a plurality of secret keys, information for designating the data section, and hash function data are input as data input shown in FIG. To be.
In addition, for the playback device 10, a plurality of pieces of information on a plurality of public keys, data sections, and hash functions are stored in advance in the ROM 27, for example.

Then, in the recording device 50, as shown in the operation (3) shown in the figure, the header data R1a is generated as a part of the reproduction permission time data as in the case of the third embodiment.
Further, in this case, as the operation of (4) shown in the figure, one secret key corresponding to the hash value obtained from the data value as the data section information and the hash function is obtained from the plurality of secret keys. select. That is, first, the encryption processing unit 55 shown in FIG. 15 recognizes the input data to be recorded on the disk 100 from the data formatter 53 based on the data section information input as described above. Recognize the data value of the data section. Then, the encryption processing unit 55 calculates a hash value based on the recognized data value and the input hash function.
Then, a secret key corresponding to this hash value is selected from the plurality of secret keys described above.

Here, the hash value is a numerical value indicated by 4 bits, 8 bits, or 32 bits, and 8 bits indicate a value of 1 to 256, for example, any of 256 encryption keys is used. You can choose what to do.
That is, in this case, the data section and the hash function should be set in advance so as to obtain the hash value corresponding to the number of encryption key pairs generated by the asymmetric encryption method generated in (1) above.

  The following operations (5) and (6) are the same as those in the second embodiment. That is, as the operation of (5), the encryption processing unit 55 encrypts the reproduction permission time data / designated server information with the selected secret key. In the operation (6), the reproduction permission time data R1b and the designated server information R1c encrypted as described above by the encryption processing unit 55 and the header data R1a generated in (3) are reproduced. The recording data R1 is generated and supplied to the data formatter 53 so that the reproduction permission time recording data R1 is recorded in a predetermined area of the disc 100.

FIG. 21 is a schematic diagram for explaining an operation performed on the reproducing apparatus 10 side when the disc 100 recorded as described above is loaded.
First, in the reproducing apparatus 10, when the reproduction permission time recording data R1 is read from the disc 100 loaded as (1), the operation of (2) is performed as follows: A hash value is obtained by a hash function.
That is, first, as described above, this data section of the loaded disc 100 is based on the data section information stored in advance on the reproducing apparatus 10 side and having the same contents as the information input on the recording apparatus 50 side. The data of the specific section indicated by the information is read out. At this time, as described above, since the data section information is set so as to designate a plaintext data portion recorded on the disc 100, the playback apparatus 10 reproduces that portion. It can be performed without decryption processing.
Then, a hash value is obtained from the value of this data and a hash function having the same content as that of the recording device 50 stored in advance on the reproducing device 10 side.
In this way, as the hash value obtained based on the information having the same contents as the recording device 50 side, the same value as the hash value obtained on the recording device 50 side can be obtained.

  As an operation of (3), one public key corresponding to the obtained hash value is selected from a plurality of public keys stored in advance. As described above, since this hash value can be the same as the hash value obtained on the recording device 50 side, depending on the operation of (3), the secret selected on the recording device 50 side. A public key to be paired with the key can be selected.

In the operation (4), the encrypted reproduction permission time data R1b is decrypted using the selected public key. That is, the reproduction permission time data R1b and the designated server information R1c encrypted with the paired secret key can be encrypted using the paired public key selected by the operation (3).
The subsequent operations (5) and (6) are the same as the operations (3) and (4) described above with reference to FIG.

FIG. 22 is a flowchart showing processing operations to be performed by the system controller 24 in order to realize the operation as the fourth embodiment described above.
In this case as well, the processing operation that should be regularly performed by the system controller 24 has already been described with reference to FIG.
First, the system controller 24 in this case also reads out the reproduction permission time recording data R1 from the disc 100 loaded by the processing in step S601. In this case, in the subsequent step S602, the data of the section designated by the data section information stored in advance is read out.

In step S603, the hash value is calculated using the data of the specific section obtained by reading and the hash function stored in advance.
In step S604, a public key is selected according to the calculated hash value.
Further, in the subsequent step S405, the encrypted reproduction permission time data R1b and the designated server information R1c in the reproduction permission time recording data R1 are decrypted using the selected public key.
When the process of step S605 is executed, the process proceeds to step S503 shown in FIG. 19, and thereafter, the same operation as in the case of the third embodiment is performed.

Thus, in the fourth embodiment, it is difficult to specify a secret key by using a plurality of sets of asymmetric encryption keys, and a secret key that is paired using a public key and a series of plaintext data and encryption data is used. Even if there is a possibility of being discovered, for example, it takes enormous costs and time to decrypt all the private keys, so that it can be virtually impossible to decrypt. If the secret key cannot be decrypted, the manufacture and distribution of the pirated disc can be prevented, that is, the content of the reproduction permission time data recorded on the disc 100 can be prevented from being falsified.
In addition, even if the secret key is taken out, it is possible to make it difficult to specify the key to be used, and this can also prevent falsification of the content of the reproduction permission time data.

In the fourth embodiment, the selection of such a key is changed depending on the value of a preset data section. For example, content data to be recorded on the disc 100 as such a data section. If the predetermined section is set, the encryption key can be changed for each content data, that is, for each movie title or music album.
Further, for example, if the recording time portion in the header data R1a is set as the data section, for example, the encryption key can be changed for each disk 100.

In the third and fourth embodiments, the first two items in the reproduction permission time data are set as the header data to be recorded on the disc 100. However, in practice, for example, the reproduction permission time data It is desirable not to fix the order of items, but to set different item data as header data.
In other words, for example, in the case where the order of items such as the content of header data is always at the head of the encrypted reproduction permission time data items, the header data corresponds to the header data from among the encrypted reproduction permission time data. There is a high possibility that the data of the part to be specified will be specified.
And depending on this, there is a possibility that the key to be used can be easily deciphered from the encrypted data specified in this way and the plaintext header data. In particular, if the method of asymmetric cryptography used is known to the outside, the strength against decryption depends only on the strength of the key. The order of items should be determined so that the order of items is not expected.

  In the third and fourth embodiments, the secret key is not read by a device other than the recording device 50, and the public key is not read by a device other than the playback device 10. The recording device 50 and the playback device 10 are preferably configured to perform mutual authentication or encrypted communication for communication with an external device.

Here, in each of the embodiments described so far, the system corresponding to the CD / DVD has been described as an example, but the present invention can also be suitably applied to configurations corresponding to other recording media.
In addition, although the example in which the content data is recorded in plain text on the disc 100 has been described, it may be configured such that the content data is encrypted and recorded, and the playback apparatus side also decrypts and plays it.
In the embodiment, the system controller 24 performs the standard time adjustment operation. However, the time counting unit 30 may be configured to perform this operation independently.

It is the figure shown about the outline | summary of the reproduction | regeneration time management system of embodiment in this invention. It is a block diagram shown about the example of an internal structure of the recording device in the reproduction | regeneration time management system of 1st Embodiment in this invention. It is a block diagram shown about the example of an internal structure of the reproducing | regenerating apparatus as embodiment. It is a schematic diagram for demonstrating the operation | movement performed in the reproduction | regeneration time management system of 1st Embodiment. It is a figure shown about the example of data recorded on a recording medium in 1st Embodiment. It is the figure which illustrated the data which should be memorize | stored in the reproducing | regenerating apparatus side. It is the flowchart shown about the processing operation which should be performed regularly as processing operation which the reproducing | regenerating apparatus of embodiment performs. 6 is a flowchart illustrating processing operations to be performed in response to loading of a storage medium as processing operations performed by the playback apparatus according to the embodiment. It is the figure which showed the example of the log | history information in implement | achieving the other example of embodiment, and the error per day and the number of days between the histories calculated according to this example. FIG. 10 is a graph showing the number of days between histories, the error between histories, and the error per day calculated according to the example of the history information shown in FIG. 9. It is a figure shown about the example of data recorded on the recording medium in 2nd Embodiment in this invention. It is the figure which illustrated the data which should be memorize | stored in the reproducing | regenerating apparatus side of the other example of 2nd Embodiment. It is a flowchart shown about the processing operation which the reproducing | regenerating apparatus of 2nd Embodiment should perform. It is a flowchart shown about the processing operation which the reproducing | regenerating apparatus of the other example of 2nd Embodiment should perform. It is a block diagram shown about the example of an internal structure of the recording device in the reproduction time management system of the 3rd and 4th embodiment in this invention. It is a schematic diagram for mainly explaining operations on the recording device side as operations performed in the reproduction time management system of the third exemplary embodiment. It is a figure shown about the example of data recorded on the recording medium in 3rd Embodiment. It is a schematic diagram for mainly explaining the operation on the playback device side as the operation performed in the playback time management system of the third embodiment. 10 is a flowchart illustrating processing operations to be performed in response to loading of a storage medium as processing operations performed by the playback apparatus according to the third embodiment. It is a schematic diagram for mainly explaining the operation on the recording apparatus side as the operation performed in the reproduction time management system of the fourth embodiment. It is a schematic diagram for mainly explaining the operation on the playback device side as the operation performed in the playback time management system of the fourth embodiment. 15 is a flowchart illustrating processing operations to be performed in response to loading of a storage medium as processing operations performed by the playback apparatus according to the fourth embodiment.

Explanation of symbols

  1 playback time management system, 10 playback device, 11 spindle motor, 12 spindle motor driver, 13 pickup, 14 slide unit, 15 servo / PLL circuit, 16 analog front-end processor, 17 CD / DVD processor, 18 host interface (I / F), 19 audio D / A conversion circuit, 20 demultiplexer, 21 audio decoder, 22 video decoder, 23 NTSC / PAL encoder and D / A conversion circuit, 24 system controller, 25 display unit, 26 operation unit, 27 ROM, 28 RAM, 29 NV-RAM, 30 time counter, 31 standard time reception processor, 32 network interface (I / F), 33 internal bus, 50 recording device, 51 additional data input unit, 52 container Tsusosu, 53 data formatter, 54 mastering unit 55 encryption processing unit, 70 network, 80 NTP server, 99 master disc, 100 disc

Claims (19)

As a playback time management system comprising a recording device and a playback device for recording and playback of a recording medium on which main data to be managed for permission / non-permission of playback is recorded,
The recording device is
Recording means for recording reproduction time data for determining a time range based on a predetermined standard time for at least permission / non-permission of reproduction of the main data on the recording medium;
The playback device is
Reproducing means for reproducing data from the recording medium;
A standard time receiving means for receiving standard time information generated by a predetermined external device connected via a network;
A timekeeping means for performing timekeeping and generating current time information,
Time correction means for correcting the current time information based on at least the standard time information received by the standard time reception means;
The reproduction time reproduced by the reproduction means when the error of the current time information based on the elapsed time from the time when the standard time information was received in the past by the standard time reception means is less than or equal to a predetermined value. Replay control means for controlling the reproduction of the main data by the replay means based on the result of comparing the time range information indicated by the data and the current time information;
A reproduction time management system.   The reproduction time management system according to claim 1, wherein the standard time receiving means is configured to receive standard time information generated by an NTP server. The recording means also records information of a predetermined error range on the recording medium,
The reproduction control means is
Whether or not the error of the current time information is equal to or less than a predetermined value based on the result of comparing the error range information in the reproduction time data reproduced by the reproducing means and the error information of the current time information. To determine whether
The reproduction time management system according to claim 1. The recording means is also adapted to record designation information for designating the external device on which the standard time receiving means should receive the standard time information on the recording medium,
The standard time receiving means is
Receiving the standard time information from the external device designated by the designation information reproduced from the recording medium by the reproduction means;
The reproduction time management system according to claim 1. The reproduction control means is
The reproduction time management system according to claim 1, wherein the reproduction process is controlled even in accordance with a determination result as to whether or not the correction of the current time information in the time counting means is not based on the standard time information. For defining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data for a recording medium on which main data to be managed for reproduction permission / non-permission is recorded A recording procedure for recording playback time data;
A standard time reception procedure for receiving standard time information generated by a predetermined external device connected via a network;
A timekeeping procedure that performs timekeeping to generate current time information,
A time correction procedure for correcting the current time information based on at least the standard time information received by the standard time reception procedure;
The reproduction time reproduced from the recording medium when the error of the current time information based on the elapsed time from the time when the standard time information was received in the past by the standard time reception procedure is less than or equal to a predetermined value. A reproduction control procedure for controlling the reproduction processing of the main data based on the result of comparing the time range information indicated by the data and the current time information;
The reproduction time management method characterized by performing. Main data to be managed for reproduction permission / non-permission, and at least reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. Reproducing means for reproducing data from a recording medium;
A standard time receiving means for receiving standard time information generated by a predetermined external device connected via a network;
A timekeeping means for performing timekeeping and generating current time information,
Time correction means for correcting the current time information based on at least the standard time information received by the standard time reception means;
The reproduction time data reproduced by the reproduction means when the error of the current time information based on the elapsed time from the time when the standard time information was received in the past by the standard time reception means is less than or equal to a predetermined value. Reproduction control means for controlling the reproduction of the main data by the reproduction means based on the result of comparing the time range information indicated by the current time information;
A playback apparatus comprising: Main data to be managed for reproduction permission / non-permission, and at least reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. As a reproduction method for reproducing data from a recording medium,
A standard time reception procedure for receiving standard time information generated by a predetermined external device connected via a network;
A timekeeping procedure that performs timekeeping to generate current time information,
A time correction procedure for correcting the current time information based on at least the standard time information received by the standard time reception procedure;
The reproduction time reproduced from the recording medium when the error of the current time information based on the elapsed time from the time when the standard time information was received in the past by the standard time reception procedure is less than or equal to a predetermined value. A reproduction control procedure for controlling the reproduction processing of the main data based on the result of comparing the time range information indicated by the data and the current time information;
A playback method characterized by executing A record in which main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data is recorded. A medium,
A recording medium, wherein information of an error range related to current time information measured by a reproducing apparatus for reproducing the recording medium is recorded. As a playback time management system comprising a recording device and a playback device for recording and playback of a recording medium on which main data to be managed for permission / non-permission of playback is recorded,
The recording device is
Recording means for recording reproduction time data for defining a time range based on a predetermined standard time for at least permission / non-permission of reproduction of the main data on the recording medium;
Recording control means for performing control so that the reproduction time data is encrypted and recorded on the recording medium based on the secret key of a secret key and a public key generated by an asymmetric encryption method; Prepared,
The playback device is
Reproducing means for reproducing data from the recording medium;
A timekeeping means for performing timekeeping and generating current time information,
The reproduction time data reproduced by the reproduction means is decrypted using the public key previously assigned to the reproduction apparatus, and information on a time range indicated by the decrypted reproduction time data Replay control means for controlling the replay of the main data by the replay means based on the result of comparison with the current time information;
A reproduction time management system. The recording control means includes
Data to be recorded in a predetermined specific section on the recording medium among the plurality of secret keys of the plurality of secret keys and the plurality of public keys generated by the asymmetric encryption method. Control to be encrypted and recorded based on one secret key selected by the value calculated from
The reproduction control means is
Of the plurality of public keys assigned to the playback device in advance, 1 is selected according to a value calculated from data obtained by playing the specific section preset from the recording medium by the playback means. The reproduction time data is decrypted using two public keys, and based on the result of comparing the time range information indicated by the decrypted reproduction time data with the current time information, the reproduction of the main data is reproduced. Configured to do control,
The reproduction time management system according to claim 10. The recording control means includes
The reproduction time data encrypted based on the secret key of the secret key and the public key generated by the asymmetric encryption method, and the partial data of the reproduction time data in plain text are used as the reproduction time recording data. Control to be recorded on the recording medium,
The reproduction control means is
Of the reproduction time record data reproduced by the reproduction means, the encrypted reproduction time data is decrypted by using the public key previously assigned to the reproduction device, and the decrypted reproduction The reproduction of the main data is controlled according to the result of comparing the coincidence between the partial data of the time data and the partial data of the plaintext reproduction time data of the reproduction time recording data. Composed,
The reproduction time management system according to claim 10. The recording control means includes
Of a plurality of secret keys generated by an asymmetric encryption method and a plurality of public keys, a value calculated from data to be recorded in a specific section on the recording medium set in advance Control is performed so that the reproduction time data encrypted based on one selected secret key and a part of the plaintext reproduction time data are recorded as reproduction time recording data on the recording medium. Done
The reproduction control means is
Of the plurality of public keys previously assigned to the playback device, the playback time data encrypted by the playback unit is recorded in the playback time record data played back by the playback unit. Decrypting by using one public key selected by a value calculated from data obtained by reproducing the specific section set in advance from the medium, and a part of the decrypted reproduction time data, It is configured to control the reproduction of the main data also according to the result of comparing the coincidence with a part of the plaintext reproduction time data of the reproduction time recording data.
The reproduction time management system according to claim 10. For determining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data for a recording medium on which main data to be managed for reproduction permission / non-permission is recorded A recording procedure for encrypting and recording the reproduction time data based on the secret key of the secret key and the public key generated by the asymmetric encryption method;
A timekeeping procedure that performs timekeeping to generate current time information,
The reproduction time data reproduced from the recording medium is decrypted using the public key assigned in advance, and the time range information indicated by the decrypted reproduction time data and the current time information are Based on the comparison result, a reproduction control procedure for controlling the reproduction process of the main data,
The reproduction time management method characterized by performing. Main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. A reproduction medium for reproducing data from a recording medium in which the reproduction time data is encrypted and recorded based on the secret key of a secret key and a public key generated by an asymmetric encryption method. Means,
A timekeeping means for performing timekeeping and generating current time information,
The reproduction time data reproduced by the reproduction means is decrypted using the public key previously assigned to the reproduction device, and information on a time range indicated by the decrypted reproduction time data A reproduction control means for controlling the reproduction of the main data by the reproduction means based on the result of comparison with the current time information;
A playback apparatus comprising: Main data to be managed for permission / non-permission of reproduction and reproduction time data for determining a time range based on at least a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. A reproduction medium for reproducing data from a recording medium in which the reproduction time data is encrypted and recorded based on the secret key of a secret key and a public key generated by an asymmetric encryption method. As a way,
A timekeeping procedure that performs timekeeping to generate current time information,
The reproduction time data reproduced from the recording medium is decrypted using the public key assigned in advance, and the time range information indicated by the decrypted reproduction time data and the current time information are Based on the comparison result, a reproduction control procedure for controlling the reproduction process of the main data,
A playback method characterized by executing Main data to be managed for reproduction permission / non-permission, and at least reproduction time data for determining a time range based on a predetermined standard time for permission / non-permission of reproduction of the main data are recorded. As a recording medium,
A recording medium, wherein the reproduction time data is encrypted and recorded based on the secret key of a secret key and a public key generated by an asymmetric encryption method. The playback time data is
Of a plurality of secret keys generated by an asymmetric encryption method and a plurality of public keys, a value calculated from data recorded in a specific section on the recording medium set in advance is selected. The recording medium according to claim 17, wherein the recording medium is encrypted and recorded based on one secret key.   The recording medium according to claim 17, wherein a part of the reproduction time data in plain text is recorded together with the reproduction time data encrypted based on the secret key.

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