JP4461183B2 - Information recording medium and playback device - Google Patents

Description

  The present invention relates to an information storage medium, a playback device, and a content protection method.

  Conventionally, secret information that is not intended to be disclosed to a user may be recorded on a storage medium such as a CD or DVD. For example, when various contents such as video, audio, and text are encrypted and recorded on a storage medium, an encryption key for decrypting the encrypted content is recorded as confidential information together with the encrypted content (for example, Patent Document 1). reference).

  In this document, main information and secret information are modulated by the first and second modulation methods, respectively, to generate a main information modulation signal and a secret information modulation signal, and a part of the main information modulation signal is converted to a secret information modulation signal. Replace and record on storage medium. That is, the embedded signal in which the confidential information modulation signal is embedded in the main information modulation signal is recorded on the storage medium. Here, in order to reduce deterioration of the signal characteristics of the main information when the secret information modulation signal is embedded in the main information modulation signal, a DC component suppression process is performed after the secret information is replaced with the main information.

  The secret information modulation / recording method should be disclosed and licensed only to the disc manufacturer and the reproduction device manufacturer who impose confidentiality. As a result, the confidential information modulation signal can be reproduced only by a reproduction apparatus manufactured by the disclosed reproduction apparatus manufacturer, and the confidentiality of information is improved. Further, the secret information modulation signal can be recorded only by a disc manufacturer who has received the disclosure, and it is difficult for an unauthorized pirate disc operator who has not received the disclosure to copy.

However, if information is accidentally leaked from a disclosure / license destination or intentionally for an unauthorized purpose, the recording / modulation method will be clarified, and the confidential information will be demodulated / reproduced. Difficulty can be compromised.
JP 2005-317136 A (paragraphs 0002 to 0005)

  As described above, the conventional information storage medium has a drawback that it cannot cope with the leakage of a secret information recording / reproduction method that is not intended to be disclosed to the user.

  An object of the present invention is to provide an information storage medium, a playback device, and a content protection method, in which the confidentiality of information and the difficulty of unauthorized copying are not impaired even if the secret information recording / playback method is leaked.

In an information recording medium according to an aspect of the present invention, content is recorded by a first recording method, the content is protected by a predetermined content protection method, and confidential information related to content protection is stored in the first recording method. Is recorded by a different second recording method , and information for implementing the second recording method, or a recording apparatus to which the method is applied, manufactures a medium approved by the administrator of the second recording method. The second recording method is recorded by the second recording method in a reproducing device that performs reproduction processing based only on the first recording method. a recording method reproducing is impossible confidential information, the first certificate relating to the content is recorded by the first recording method, the second recording method Administrator, at least a portion of the second certificate to be provided to the medium manufacturer took a predetermined procedure is recorded by the second recording method, the first certificate, the medium manufacturer said content Prior to manufacturing the recorded medium, each content is provided by an administrator of the content protection method based on a request from the medium manufacturer, and the second certificate is provided by the medium manufacturer in the second recording method. In order to continuously use the content, the media manufacturer needs to update regularly, and before the media manufacturer manufactures the media on which the content is recorded, the second information is requested based on the request from the media manufacturer at regular intervals. Provided by the administrator of the recording method, the first certificate is the first date / time identification information generated based on the first date / time when the first certificate was issued, and the manufacturer of the medium recording the content Identification information, and Including a digital signature, wherein the second certificate includes second date and time identification information generated based on a second date and time when the second certificate was issued, identification information of a manufacturer of the medium on which the content is recorded, and It includes a digital signature.

In a playback apparatus according to another aspect of the present invention, content is recorded by a first recording method, the content is protected by a predetermined content protection method, and confidential information relating to content protection is the first recording method. A recording device that is recorded by a different second recording method and to which the second recording method is implemented or a recording device to which the second recording method is applied is a manufacturer of a medium that has been approved by the administrator of the second recording method. The second recording method is disclosed only to the manufacturer of the medium manufacturing device and the manufacturer of the reproducing device, and the second recording method is recorded by the second recording method in a reproducing device that performs reproduction processing based only on the first recording method. and a recording system reproducing is impossible confidential information, the first certificate relating to the content is recorded by the first recording method, the administrator of the second recording method At least a portion of the second certificate to be provided to the medium manufacturer took a predetermined procedure is recorded by the second recording method, the first certificate, the medium in which the medium manufacturer has recorded the content Prior to manufacturing, the content protection method administrator provides each content based on the request of the medium manufacturer, and the second certificate is continuously recorded by the medium manufacturer in the second recording method. Management of the second recording method is required based on the request of the medium manufacturer at regular intervals before the medium manufacturer manufactures the medium on which the content is recorded. It is provided by user, the first certificate, the first day when the identification information stored in the first certificate is generated based on when the first day issued, manufacturer identification information of the medium recording the content, and Digital station The second certificate includes second date and time identification information generated based on a second date and time when the second certificate was issued, identification information of a manufacturer of the medium on which the content is recorded, and a digital signature A reproducing apparatus for reproducing information from an information recording medium, comprising:
Means for reading the first certificate and the second certificate;
The first date / time identification information included in the first certificate is compared with the second date / time identification information included in the second certificate, and either the first date / time identification information or the second date / time identification information is compared. Based on either of these, a means for permitting reproduction of the content if the other date and time identification information is within a predetermined range, and prohibiting the content otherwise ,
It is characterized by comprising.

  As described above, according to the present invention, it is possible to provide an information storage medium, a playback device, and a content protection method that do not impair the confidentiality of information and the difficulty of unauthorized duplication even if the recording / playback method of confidential information is leaked. Can do.

  In the embodiment of the present invention, confidential information that is not intended to be disclosed to the user is recorded by a special recording method, and a new concept of a certificate relating to a license for the method is introduced. For example, the certificate is provided to the disc manufacturing (plate making) company by the disclosure / license manager of the special recording / reproducing method. The certificate includes identification information on the date and time when the certificate is issued, disc manufacturer identification information, a signature, and the like. The disc manufacturer records the certificate together with the secret information when recording the confidential information on the disc. The playback device checks the certificate when playing back the confidential information by the special recording / playback method, and cannot play back the medium if the certificate does not meet a predetermined condition. As a result, the disc manufacturer who is the disclosure destination / license recipient can use the special recording / reproduction method only under the authorization of the disclosure source / license manager.

  For example, the disclosure source / license manager appropriately updates the certificate so that the special recording / reproducing method cannot be used without the latest certificate. If the date / time identification information is included in the certificate, the disc manufacturer cannot use the special recording / reproducing method without obtaining the latest certificate at regular intervals. If the special recording / reproducing system is illegally leaked, the discriminator / license manager will not renew the certificate to the disc manufacturer if the disc manufacturer who has committed the illegal act can be identified.

  On the other hand, the playback device compares the date and time identification information of the certificate with the date and time identification information transmitted by another means. As another means, a method of acquiring information recorded in other areas of the disc, a method of acquiring information from a network or other medium, and information transmitted from these to a nonvolatile memory included in the playback device itself A method of holding and using this can be considered. Also for the disc manufacturer identification information, the playback apparatus compares the disc manufacturer identification information of the certificate with the identification information transmitted by the other means.

For this reason, if the playback device has an old certificate, or if the certificate is from an unauthorized disc manufacturer, it is impossible to play back confidential information or play content using it. And

  Thereby, even if the special recording / reproducing method is leaked, the confidential information is not reproduced from the medium on which the correct certificate is not recorded.

  Hereinafter, an embodiment of a content protection method including a playback apparatus for playing back an information storage medium according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a system when the present invention is applied to a copyright protection system represented by CPPM (Content Protection for Prerecorded Media), AACS (Advanced Access Content System), etc. used in a read-only optical disc. FIG.

  The system includes four subsystems: a key manager 10, a medium manufacturer 12, a playback device manufacturer 14, and a special recording / playback system manager 16.

  First, the medium manufacturer 12 side will be described. The server of the key manager 10 of the copyright protection management mechanism such as AACS, CPPM, etc. is presented by the key (encryption key) used for content encryption or the media manufacturer 12. A content certificate (including content information) for the content information is generated and provided to the client of the medium manufacturer 12. The client of the medium manufacturer 12 uses these to encrypt the content, and manufactures a medium on which the encrypted content is recorded. The medium is a read-only medium, and manufacturing is performed by forming a substrate using a stamper. Cryptographic key or confidential information equivalent to it (details will be described later, but this data includes KCD and volume ID that are the source of the cryptographic key) or are not easily revealed or difficult to duplicate Record on media. Content is recorded by a normal open recording method. Information for implementing the special recording method or a recording apparatus to which the special recording method is applied is provided from the special recording / reproducing method manager 16 to the medium manufacturer 12. The special recording / playback system manager 16 provides a certificate (hereinafter referred to as a media mark certificate) to certify that an authorized medium manufacturer 12 who has taken a predetermined procedure has received authorization to use the system. I will provide a. The medium manufacturer 12 records confidential information on the medium by a special recording method, and also records a media mark certificate on the medium by a special recording method. However, the special recording method for recording the confidential information and the media mark certificate is not the same, and another special recording method may be used.

  Referring to the playback device manufacturer 14 side, the key manager 10 includes an encryption key used for content recording, a decryption key that is paired with a content certificate and used for content playback, and a CC (content certificate). A verification key or the like is generated and provided to the playback device manufacturer 14. The playback device uses these to decrypt the content, verify the signature of the content certificate, and the like. In content decryption, as will be described later, in general, content is not decrypted with the decryption key itself, but decryption generally has a hierarchical structure. In order to perform final content decryption, it is necessary to reproduce the confidential information recorded by the special recording method by the special reproduction method. Information for implementing the special reproduction method or a reproduction device to which the special reproduction method is applied is provided from the special recording / reproduction method administrator 16 to the reproduction device manufacturer 14. At this time, the MM (media mark) verification key for verifying the media mark certificate for certifying that the authorization for using the special recording / reproducing method recorded on the medium has been obtained is also the special recording / reproducing method. Provided by the administrator 16 to the playback device manufacturer 14.

  FIG. 2 shows an example of the generation process of the encryption key group and the content certificate in the key manager 10. Normally, content on a medium is encrypted with a key called a title key. The title key is recorded on the medium in an encrypted state. The key used for encrypting the title key is called a media key, which is generated by the key manager 10. The media key is further encrypted with the device key to form a media key block (MKB). The MKB is recorded on the medium together with the encrypted content and the encrypted title key.

  Depending on the copyright protection system, the media key itself may not be encrypted with the device key, but the media key precursor, which is the original information of the media key, may be encrypted using the device key as shown in the encryption unit 22. is there. As shown in the encryption unit 24, the media key is a result of performing a key generation process on the media key precursor and the key conversion data (KCD) using, for example, a one-way function. The media key, KCD, and MKB are provided to the media manufacturer 12 together with the content certificate, and the device key set is provided to the playback device manufacturer 14.

  Further, the key manager 10 may generate a content certificate based on the content specific information. The content specific information may include content identification information (ID) given by the key manager 10, date and time identification information, content information provided by the medium manufacturer 12, or a combination thereof. In order to prevent forgery, a content certificate is often given a signature by a private key / public key algorithm. In this case, the content certificate is provided to the medium manufacturer 12 and the signature verification key is provided to the playback device manufacturer 14.

  FIG. 3 shows an example of the special recording / reproduction method and the media mark certificate management / generation process associated with the special recording / reproduction method manager 16. The special recording / playback method is a method of recording information in a physical layer on a read-only disc in a concealed manner, and it is required to conceal the volume ID and value that are required to be unable to be copied bit by bit. Used for recording KCD. Information for implementing the special recording / reproducing method, or the recording device / reproducing device 36 to which the special recording / reproducing method is applied, is usually provided after a confidentiality agreement or the like is made to the medium manufacturer 12 and the reproducing device provider 14. A media mark certificate is generated to indicate permission for use of the special recording / playback method. The media mark certificate generation unit 34 combines the signature key generated by the key generation unit 32 with identification information for distinguishing the provider of the special recording / playback method, date / time identification information, random number, fixed value, signature, etc. Is generated. The key generation unit 32 generates a signature key using a secret key / public key algorithm or the like. The key generation unit 32 also generates an MM verification key for verifying the signature of the media mark certificate. The media manufacturer 12 is provided with a media mark certificate, and the playback device manufacturer 14 is provided with an MM verification key.

  FIG. 4 shows an example of the configuration of the media mark certificate. The media mark certificate includes date and time identification information, manufacturer identification information, a random number, and a signature. The date and time identification information indicates the date and time when the media mark certificate is issued, and is used for the purpose of indicating the expiration date of the media mark certificate. If the special recording / reproduction method and media mark certificate are illegally leaked or copied by a malicious media manufacturer and the confidentiality of the special recording / reproduction method and media mark certificate is lost, the manufacturer identification information It is used for the purpose of identifying a person. The random number is assigned with a length determined by a request for a signature algorithm of the media mark certificate and a constraint condition of the media mark certificate data length. A case where the random number is a fixed value is also conceivable. The signature is given to prevent forgery of the media mark certificate. FIG. 4 is an example. When there is no date and time identification information, when there is no manufacturer identification information, there may be a case where there is no random number, and the configuration can be changed depending on the purpose.

  FIG. 5 shows an example of the configuration of the content certificate. The content certificate is a content ID that is identification information of the content, a unique value that is a result of performing a predetermined calculation on part or all of the content, a hash value that is used to prevent content tampering, and a content certificate It consists of a signature to prevent counterfeiting and others. The date / time identification information of the media mark certificate, the date / time identification information to be compared with the manufacturer identification information, and the manufacturer identification information may be included in the content ID or may be described elsewhere. FIG. 5 is an example, and the configuration can be variously changed.

  FIG. 6 shows an example of the process of encrypting the content and recording the encrypted content on the medium in the medium manufacturer 12. As described above, a content certificate, MKB, media key, and KCD are given from the key manager 10. Further, the special recording / playback system manager 16 gives information (or a recording apparatus to which the system is applied) 50 and a media mark certificate for implementing the special recording system. On the other hand, a content creator (right holder) provides a medium unique ID (volume ID), a title key, and content.

  The content certificate, MKB, and media mark certificate are recorded on the medium 100 as they are by a normal recording method. At least one of the volume ID and the KCD is recorded on the medium 100 by the secret recording method which is a special method different from the normal recording method in the secret information recording unit 52 based on the information 50 for implementing the special recording method. Even when both the volume ID and the KCD are recorded by the secret recording method, both may be recorded by using different special recording methods.

  The title key is encrypted by the encryption unit 56 using the volume unique key generated by the key generation unit 54 based on the volume ID and the media key, and is recorded on the medium 100. The content is encrypted by the encryption unit 58 based on the title key and recorded on the medium 100. The encrypted title key and the encrypted content are recorded by a normal recording method.

  FIG. 7 shows an example of a content reproduction process in the reproduction apparatus. As described above, the key manager 10 provides a device key and a CC verification key. The special recording / playback system administrator 16 provides information (or a playback apparatus to which the special recording / playback system 60 is implemented) 60 and an MM verification key.

  In the playback device, the MKB, media mark certificate, content certificate, encrypted title key, and encrypted content are played back by a normal playback method. The MKB is decrypted by the decryption unit 62 using the device key to obtain a media key precursor.

  The media mark certificate is authenticated by the signature / identification information confirmation unit 64 using the content certificate.

  The volume ID and / or KCD recorded by the special recording method is reproduced by the secret information reproducing unit 66 by the special reproduction method. The KCD is supplied to the key generation unit 68 via the switch 200 whose conduction is controlled based on the authentication result of the signature / identification information confirmation unit 64, and a media key is generated using a media precursor.

  The volume ID is supplied to the key generation unit 70 via the switch 202 whose conduction is controlled based on the authentication result of the signature / identification information confirmation unit 64, and a volume unique key is generated using the media key.

  The encrypted title key is decrypted by the decryption unit 72 using the volume unique key generated by the key generation unit 70, and a title key is generated.

  The encrypted content is decrypted by the decrypting unit 74 using the title key. The content decrypted by the decryption unit 74 is output via the switch 204 whose conduction is controlled based on the authentication result of the signature / identification information confirmation unit 64.

  The signature / identification information confirmation unit 64 confirms the media mark certificate with the MM verification key. When it is confirmed that the media mark certificate is valid, the following processing is executed. For example, as described in FIG. 5, when the date / time identification information of the media mark certificate, the date / time identification information that can be compared with the manufacturer identification information, and the manufacturer identification information are included in the content ID of the content certificate, Both are compared, and only when the relationship between the two matches a predetermined condition, the reproduction of the confidential information and the reproduction of the content are permitted (implemented). Details of this comparison / determination will be described later. The information that can be compared / determined is not limited to using both the date and time identification information and the manufacturer identification information, and may be at least one or other information. In addition, when the content certificate also includes a signature, processing for confirming the validity of the content certificate with the CC verification key is performed on the playback device side. By making the switches 200 and 202 conductive only when the authentication result of the signature / identification information confirmation unit 64 is correct, even if the special recording / reproducing method is leaked and the confidential information (KCD, volume ID) is reproduced, the confidential information is not generated. Since the keys are not supplied to the key generation units 68 and 70, the key generation units 68 and 70 cannot generate a key, and thus the encrypted content cannot be decrypted. Further, the switch 204 connected to the output of the content decryption unit 74 is turned on only when the authentication result of the signature / identification information confirmation unit 64 is correct, so that even if the special recording / reproducing method is leaked, the confidential information (KCD, volume) Even if (ID) is reproduced, the decrypted content cannot be output. As described above, the playback device verifies the content certificate and the media mark certificate recorded on the medium prior to playback of the content, and permits / prohibits playback of the content according to the verification result.

  FIG. 8 shows an example of the media mark certificate and content certificate verification process in the playback apparatus. FIG. 8 is a flowchart mainly showing the operation of the signature / identification information confirmation unit 64.

  As shown in block # 102, the signature of the media mark certificate is confirmed by the MM verification key. If the signature is not valid, playback is stopped as indicated by block # 110. If it is valid, the signature of the content certificate is confirmed by the CC verification key as shown in block # 104. If the signature is not valid, playback is stopped as indicated by block # 110. If it is valid, as shown in block # 106, the contents of the media mark certificate and the content certificate are compared and confirmed. If the condition is met, the process proceeds to the next process (content reproduction process shown in block # 108). If the condition is not met, the reproduction is stopped as shown in block # 110.

  As an example of the determination of block # 106, when both of the media mark certificate and the content certificate include date and time identification information, one of the date and time identification information is used as a reference, and the other date and time identification information is within a predetermined range. If the condition is met, the condition is not met. For example, when the date and time identification information of the media mark certificate is MMT and the date and time identification information of the content certificate is CCT, conditions such as CCT-N <MMT and / or MMT <CCT + M can be considered. Here, N and M are date and time identification information indicating year, month, date, time, and the like. This requires periodic updating of both certificates, but by preventing unauthorized users from obtaining updated certificates, it is possible to prevent unauthorized use of content due to diversion of old certificates that have not been updated.

  Other examples of the determination of block # 106 include cases where both the media mark certificate and the content certificate include the media manufacturer identification information, when they are compared and matched, or according to a predetermined white list or black list As a result of the identification, if it is identified that the medium manufacturer 12 is a licensed, the condition is met, otherwise the condition is not met. This also prevents any certificate from being misappropriated by another medium manufacturer 12.

  Note that the date / time identification information and manufacturer identification information do not need to be included in the content certificate, but may be included in other data, or compared with a clock or manufacturer list on the playback device side. May be.

  FIG. 9 shows another example of the media mark certificate verification process. FIG. 9 shows an example of a media mark certificate confirmation process in the case of a playback apparatus having a limited function. The playback apparatus described above with reference to FIG. 7 has generally been exemplified based on a video playback player for consumer use. Other than this, the playback apparatus itself does not have a video playback function, but an example of an optical disk drive that realizes playback by combining with a software player on a personal computer is conceivable. In general, such an optical disc drive cannot read a content certificate recorded under management on a file system, and can read only a media mark certificate.

  As shown in block # 112, the optical disc drive confirms the signature of the media mark certificate with the MM verification key. If the signature is not valid, the output of confidential information is not permitted as shown in block # 116. If it is valid, output of confidential information is permitted as shown in block # 114. In addition to permitting / disapproving the output of the secret information of blocks # 114 and # 116, or alternatively, outputting of the decrypted content itself may be permitted / not permitted. Further, a predetermined authentication process may be added by a software player and a drive on the personal computer side in the secret information or content output stage.

  In the recording process of FIG. 6, the media mark certificate is recorded by a normal recording method, but at least a part or all of the media mark certificate may be recorded by a secret recording method. FIG. 10 shows a modification in which at least a part is recorded by the secret recording method. A difference from FIG. 6 is that a part of the media mark certificate is supplied to the confidential information recording unit 52. When the media manufacturer 12 who tries to divert all of the date / time identification information, the media mark certificate including the manufacturer identification information, and the content certificate appears, it is difficult to prevent with the system of FIG. For this reason, at least a part of the media mark certificate is recorded on the medium by the secret recording method, which is a special recording method, so that it cannot be read out by a general device, and unauthorized use of the media mark certificate is prevented. be able to. The secret recording method of the media mark certificate and the recording method of so-called secret information such as KCD and volume ID may be the same or different.

  FIG. 11 is a modification of the reproduction process corresponding to the recording process of FIG. 10, and at least a part of the media mark certificate is reproduced by the confidential information reproduction unit 66. As a part of the media mark certificate recorded by the confidential method, date identification information, manufacturer identification information, and a random number part (that is, a part other than a signature) can be considered, but the present invention is not limited to this.

  As described above, according to the present embodiment, the content is recorded on the medium by the normal recording method, the confidential information regarding the protection of the content is recorded on the medium by the special confidential recording method, and the usage permission of the confidential recording method is concerned. Since the media mark certificate is recorded on the medium, the content can be reproduced only from the medium on which the valid media mark certificate is recorded. This is because a legitimate media mark certificate can be recorded on a medium only by a medium manufacturer who has received a license for use of the secret recording method. The validity of the media mark certificate can be determined based on the identification information of the date and time when the media mark certificate is issued, the identification information of the medium manufacturer, or the like. If the media mark certificate is renewed periodically based on the date / time identification information, illegal reproduction of content due to the diversion of the old media mark certificate owned by the media manufacturer who is not licensed can be prevented. . Thereby, it is possible to set the expiration date of the license for use of the secret recording method, and it is possible to validate the license only for a medium manufacturer that is correctly operating the secret recording method. When based on the identification information of the medium manufacturer, it is possible to prohibit reproduction of an unauthorized medium manufactured by an unauthorized medium manufacturer according to the black list or the white list. As a result, it is possible to manage the activation of the individual confidential recording method for each medium manufacturer, and if the confidential recording method is used illegally, it becomes easy to track the unauthorized media manufacturer. In addition, it is possible to realize management for preventing illegal use and outflow of a special recording / reproducing method for preventing unauthorized duplication of confidential information. Furthermore, illegal recording of the media mark certificate becomes impossible by recording at least a part of the media mark certificate on the medium by a special recording method that cannot be easily read. These effects can be obtained individually or in combination.

  The present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment. The playback device described above may be a recording / playback device. Further, the playback device may have a software configuration or a hardware configuration. The content and key encryption / decryption processes are examples, and variations are also conceivable. Even in this case, the effect of incorporating the special recording / reproducing method, the media mark certificate, and the MM verification key remains the same. Furthermore, the comparison target of the date / time identification information and the manufacturer identification information is not limited to that in the content certificate, but may be information obtained by a medium or communication, or may be information held by the playback apparatus itself. . Information that uses the special recording / reproduction method is not limited to confidential information, but information that requires difficulty in preventing duplication, or the data structure itself formed by the special recording / reproduction method is meaningful and information to be recorded is It can be applied to any case. The medium is not limited to the read-only type, and the same effect can be obtained even if the medium manufacturer is replaced with a recording device and a recording medium. Further, the medium is not limited to an optical disk but can be applied to a semiconductor memory, a magnetic recording disk, and the like.

  The present invention can also be implemented to cause a computer to execute predetermined means, to cause a computer to function as predetermined means, to cause a computer to realize predetermined functions, or as a computer-readable storage medium storing a program. You can also

The figure which shows an example of the system configuration at the time of applying this invention to a copyright protection system. The figure which shows an example of a process of a key administrator. The figure which shows an example of a process of a special recording / reproducing system manager. The figure which shows an example of the media mark certificate which a special recording / reproducing system administrator produces | generates. The figure which shows an example of the content certificate which a key administrator produces | generates. The figure which shows an example of a medium manufacturer's process. The figure which shows an example of the process of a reproducing | regenerating apparatus. The figure which shows an example of the verification process of the media mark certificate and content certificate in a reproducing | regenerating apparatus. The figure which shows an example of the verification process of the media mark certificate in a reproducing | regenerating apparatus. The figure which shows another example of a medium manufacturer's process. The figure which shows another example of the process of a reproducing | regenerating apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Key manager, 12 ... Medium manufacturer, 14 ... Playback apparatus manufacturer, 16 ... Special recording / reproducing system manager, 52 ... Secret information recording part, 54 ... Volume unique key generation part, 56 ... Title key encryption part 58 ... Content encryption unit, 64 ... Signature / identification information confirmation unit, 66 ... Confidential information reproduction unit, 68 ... Media key generation unit, 70 ... Volume unique key generation unit, 72 ... Title key decryption unit, 74 ... Content Decryption unit.

Claims (2)

The content is recorded by the first recording method,
The content is protected by a predetermined content protection method,
Confidential information related to content protection is recorded by a second recording method different from the first recording method,
Information for implementing the second recording method, or a recording apparatus to which the method is applied, includes a manufacturer of a medium authorized by an administrator of the second recording method, a manufacturer of the medium manufacturing device, and Only disclosed to the manufacturer of the playback device,
The second recording method is a recording method in which confidential information recorded by the second recording method cannot be reproduced in a reproducing apparatus that performs a reproduction process based only on the first recording method,
A first certificate relating to the content is recorded by a first recording method;
An administrator of the second recording method records at least a part of a second certificate provided to the medium manufacturer that has taken a predetermined procedure by the second recording method,
The first certificate is provided by an administrator of the content protection method based on a request from the medium manufacturer for each content before the medium manufacturer manufactures the medium on which the content is recorded.
The second certificate needs to be updated periodically in order for the media manufacturer to continuously use the second recording method, and prior to the media manufacturer producing the media on which the content is recorded. , Provided by the administrator of the second recording method based on the request of the medium manufacturer at regular intervals,
The first certificate includes first date and time identification information generated based on a first date and time when the first certificate is issued, identification information of a manufacturer of a medium on which the content is recorded, and a digital signature.
The second certificate includes second date and time identification information generated based on a second date and time when the second certificate is issued, identification information of a manufacturer of the medium on which the content is recorded, and a digital signature. An information recording medium characterized by the above. The content is recorded by the first recording method,
The content is protected by a predetermined content protection method,
Confidential information related to content protection is recorded by a second recording method different from the first recording method,
Information for implementing the second recording method, or a recording apparatus to which the method is applied, includes a manufacturer of a medium authorized by an administrator of the second recording method, a manufacturer of the medium manufacturing device, and Only disclosed to the manufacturer of the playback device,
The second recording method is a recording method in which confidential information recorded by the second recording method cannot be reproduced in a reproducing apparatus that performs a reproduction process based only on the first recording method,
A first certificate relating to the content is recorded by a first recording method;
An administrator of the second recording method records at least a part of a second certificate provided to the medium manufacturer that has taken a predetermined procedure by the second recording method,
The first certificate is provided by an administrator of the content protection method based on a request from the medium manufacturer for each content before the medium manufacturer manufactures the medium on which the content is recorded.
The second certificate needs to be updated periodically in order for the media manufacturer to continuously use the second recording method, and prior to the media manufacturer producing the media on which the content is recorded. , Provided by the administrator of the second recording method based on the request of the medium manufacturer at regular intervals,
The first certificate includes first date and time identification information generated based on a first date and time when the first certificate is issued, identification information of a manufacturer of a medium on which the content is recorded, and a digital signature. The second certificate includes second date and time identification information generated based on a second date and time when the second certificate is issued, identification information of a manufacturer of a medium on which the content is recorded, and a digital signature. A reproducing apparatus for reproducing information from an information recording medium characterized by:
Means for reading the first certificate and the second certificate;
The first date / time identification information included in the first certificate is compared with the second date / time identification information included in the second certificate, and either the first date / time identification information or the second date / time identification information is compared. Based on either of these, a means for permitting reproduction of the content if the other date and time identification information is within a predetermined range, and prohibiting the content otherwise ,
A playback apparatus comprising:

Images