JP2004311000A - Recording device and copyright protection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording apparatus for recording contents on a recording medium, which is compatible with a plurality of copyright protection recording methods.
A recording apparatus includes: a receiving unit that receives content; a control unit that determines a content recording method for a recording medium; and an R / W unit that writes and reads a recording medium. The control unit 302 includes a recording medium specifying unit 302a that specifies the type of the recording medium via the R / W unit 305, and a source specification that determines the type of the source as to whether the received content is a content to be protected by copyright. A recording method selection unit 302c for selecting a recording method of the content on the recording medium 120; and a recording method conversion unit 302d for converting the recording method.
[Selection diagram] FIG.

Description

  The present invention relates to a recording apparatus and a copyright protection system (CPS: Content Protection System) used when recording digitized data of content such as a movie or music on a recording medium such as an optical disk, The present invention relates to a recording apparatus and a copyright protection system that can cope with the copyright protection recording method.

  In recent years, with the development of multimedia-related technology, the emergence of large-capacity recording media, and the like, digital content (hereinafter, content) composed of moving images, audio, and the like is generated and stored on a large-capacity recording medium such as an optical disk and distributed. Systems that distribute or distribute via networks have emerged. The distributed content is to be recorded on a recording medium such as a DVD using a recording device, and is read by a computer or a reproducing device to be reproduced.

  Generally, encryption technology is used to protect the copyright of content, that is, to prevent unauthorized use of the content, such as unauthorized reproduction or copying, and a method of encrypting the content and recording it on a recording medium is used. Is a method of encrypting and recording the content itself with an encryption key corresponding to the decryption key held by the terminal, or encrypting and recording the content with a certain key, and then decrypting the decryption key corresponding to the key. There is a method of encrypting and recording with an encryption key corresponding to the decryption key held by the terminal.

  At this time, the decryption key held by the terminal needs to be strictly managed so as not to be exposed to the outside, but there is a risk that a certain key may be exposed to the outside in the analysis inside the terminal by an unauthorized person. Once a certain key is exposed to an unauthorized person, it is conceivable to create a recording device, a reproducing device, or software for illegally using the content and distribute them through the Internet or the like. In such a case, the copyright owner wants to make it impossible to handle the contents to be provided next with the key once exposed. A technique for realizing this is called a key revocation technique (for example, see Patent Document 1).

FIG. 12 is an explanatory diagram for explaining the key revocation technique. In the copyright protection system using this key revocation technology, the medium unique information (MID: Media ID) 1203 and the key revocation data (KRD: Key Revocation Data) 1202 are written in the non-writable area 1201a of the recording medium 1201. It is characterized by.
In FIG. 12, a recording medium 1201 such as an optical disk has a non-rewritable area 1201a and a rewritable area 1201b. The non-rewritable area 1201a is an area that can be read only, and has recorded therein key revocation data (KRD) 1202 and medium unique number (MID) 1203. In the rewritable area 1201b, an encrypted content key 1204 and an encrypted content 1205 are recorded.

  In a normal state, the device 1 (1206) such as a playback device uses a device key 1 (Devkey1) unique to the device to use the encrypted content recorded on the recording medium 1201. (E) is decrypted to obtain a media key (MK), and using this media key (MK), the cipher text of the encrypted content key 1204 is decrypted to obtain a content key (CK). The content can be reproduced by decrypting the encrypted content 1205 using (CK).

  Then, for example, when the device key 2 (Devkey 2) corresponding to the device 2 is exposed by an unauthorized person, even if the encrypted text (E) in the key revocation data 1202 is decrypted, the regular media key (MK) is obtained. No, only invalidated data (xxx) can be obtained. For this reason, the device 2 cannot decrypt the legitimate content key (CK) and cannot illegally use the content.

  As described above, in the key revocation technology, which is a copyright protection system, the key used for decryption (the device key 2 in this figure) is revoked using the key revocation data 1202, so that the illegal use of the content is performed. Prevention.

  On the other hand, reading or writing of content recorded on a recording medium such as an optical disk is generally performed by a personal computer peripheral device called an optical disk drive. It is common that the input / output method is standardized as public information and is not kept secret. Therefore, the content recorded on the recording medium can be easily read by a personal computer or the like, and the read data can be easily written on another recording medium. Therefore, in a system for protecting the copyright of content, a system having an effective function of preventing an action that can be performed by a normal user, that is, reading data on a recording medium and writing the data on another recording medium. Must. As a technique for achieving such an object, there is a technique called a so-called media binding for preventing content duplication by recording content in association with an individual recording medium (for example, see Patent Document 2). This media bind technology is a technology for encrypting content using a medium unique number (MID) recorded in a non-rewritable area of a recording medium.

As a specific example of the copyright protection system having the function of the key revocation technology or the media binding technology, there is a CPRM (Content Protection for Recordable Media) recording method used in a DVD-RAM or the like.
Conventionally, there is a recording apparatus that supports only the CPRM recording method as a copyright protection system. FIG. 13 is an explanatory diagram of a recording device 1301 corresponding to a conventional single copyright protection system.

  The recording device 1301 is a device for receiving content from a broadcast, a DVD, or the like, and recording the content on a recording medium 1303 or the like, and includes a recording method selection unit 1302. The recording method selection unit 1302 determines the source type of the copyright protected content (CP content) or the content that does not require copyright protection (Non-CP content) to protect the copyright, and the recording media 1303 and 1304. A selection is made as to whether or not to record content by the CPRM recording method according to the type.

The recording method selection unit 1302 selects a recording method according to the type of the source. If the content is a content that requires copyright protection, the recording method selection unit 1302 selects the CPRM recording method and requires copyright protection. If the content is not set, the non-CP recording method is selected.
The recording method selection unit 1302 selects a recording method according to the type of the recording medium 1303 or the like. Since the medium unique number (MID) and the key revocation data (KRD) are written in the recording medium 1303, the recording method selection unit 1302 uses the CPRM recording method or the Non-CP recording method that does not perform copyright protection. Select whether to record content.

In addition, since the recording medium 1304 does not have the medium unique information (MID) and the key revocation data (KRD) written therein, the recording method selecting unit 1302 records the content in the non-CP recording method that does not perform copyright protection. Choose to do. Note that a case where the recording of the content from the recording device 1301 to the recording medium cannot be performed is NG.
JP-A-2002-281013 Japanese Patent No. 3073590

  With the progress of digital technology in recent years, as described above, a plurality of copyright protection systems other than the above-mentioned conventional copyright protection systems are scheduled to be introduced in the copyright protection system for content distribution. In such a situation, the recording apparatus and the reproducing apparatus need to support a new copyright protection system other than the conventional copyright protection system such as the CPRM recording method described above. That is, there is a demand for a recording device that can support a plurality of copyright protection systems, such as a conventional copyright protection system and a new copyright protection system.

However, the above-mentioned conventional recording device 1301 is a recording device corresponding to a single copyright protection recording method, for example, a CPRM recording method, and is a current copyright protection system and a new copyright protection system to be introduced in the future. There is no recording device that can support a plurality of copyright protection recording methods corresponding to.
By the way, in the reproducing apparatus, there is a reproducing apparatus corresponding to a plurality of copyright protection systems. Specifically, current DVD-RAM recorders can reproduce content by supporting both the CSS recording method and the CPRM recording method, which are copyright protection systems.

  With the advancement of the copyright protection system, the appearance of a multi-disc that supports a plurality of copyright protection systems on one disc is expected. However, conventional discs are compatible with a single copyright protection system, and can move and copy content between server devices and recording devices using multiple discs that support multiple copyright protection systems. There is no copyright protection system.

Furthermore, there is a demand for further copyright protection in content distribution under a situation in which a mechanism for realizing movement and copying of content within a home is being established with the spread of home networks.
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a recording apparatus for recording contents on a recording medium not only supports a conventional copyright protection system but also supports a plurality of new copyright protection systems. A first object is to provide a possible recording device.

  Also, as a second object, when there are a plurality of copyright protection recording methods, the content from the server device is determined according to the function of the recording device to which the content is distributed and the type of recording medium on which the content is recorded. An object of the present invention is to provide a copyright protection system for efficiently distributing a copyright.

  In order to solve the above-mentioned problems, the present invention provides a recording apparatus for recording content that is a digital work on a recording medium, comprising: a content acquisition unit configured to acquire content provided from outside; and a type of received content. Content type specifying means for specifying the type of the recording medium, the recording medium type specifying means for specifying the type of the recording medium, and the type of the content specified by the content type specifying means and the recording medium specified by the recording medium type specifying means. Recording means for selecting at least one recording method from a plurality of recording methods based on the type; and recording means for recording the content on the recording medium in accordance with the selected recording method. And

  Note that the present invention can be realized not only as a recording device as described above, but also as a recording method in which units provided in the recording device are steps, or as a program for realizing the recording method by a computer or the like. It goes without saying that the program can be distributed via a recording medium such as an optical disk or a CD-ROM or a transmission medium such as a communication network.

  As is apparent from the above description, the recording device according to the present invention is a recording device that records content that is a digital work on a recording medium, and a content acquisition unit that acquires content provided from the outside, Content type specifying means for specifying the type of the specified content, recording medium type specifying means for specifying the type of the recording medium, and the content type specified by the content type specifying means and the recording medium type specifying means Recording method selecting means for selecting at least one recording method from a plurality of recording methods based on the type of the recording medium, and recording means for recording the content on the recording medium according to the selected recording method. It is characterized by having.

  Thereby, the recording apparatus can select a recording method of the content on the recording medium according to the type of the recording medium, the type of the content, and the like from the plurality of copyright protection recording methods.

  Also, in the recording apparatus according to the present invention, the content acquisition unit transmits the acquired content to the recording unit via a transmission path, and the recording unit records the content received via the transmission path. The content is recorded on a medium, and the content acquisition unit encrypts the content according to a recording method adopted by a recording unit serving as a transmission destination, and then transmits the encrypted content to the recording unit.

  Therefore, when transmitting the encrypted content to the recording device, the server device selects a content distribution method according to the type of the recording device to which the content is to be distributed or the type of the recording medium on which the content is to be recorded. Therefore, the server device that is the content distribution source can distribute the content according to the capability of the recording device of the distribution destination or the type of the recording medium on which the content is recorded, and realize more efficient content distribution. can do.

Hereinafter, a recording device and a copyright protection system according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment)
First, the CPS-2 recording system used in the copyright protection system according to the present embodiment, which is different from the above-described conventional CPRM recording system, will be described. The CPS-2 recording method is characterized in that an authenticator (MAC) is generated from a medium unique number (MID) which is a number unique to a recording medium.

  FIG. 1 is a schematic diagram showing an entire configuration of a CPS-2 recording system used in a copyright protection system used in the present embodiment. FIG. 1 is a block diagram illustrating a configuration of a recording device 100 that records on a recording medium 120 such as an optical disk, information recorded on the recording medium 120 from the recording device 100, and reproduction of content using the recording medium 120. A block diagram showing the configuration of the playback device 200 is shown, and the relationship between the processing units is indicated by arrows.

  The recording device 100 includes a device key storage unit 101 that stores a device key secretly held by each recording device 100, and a key revocation that acquires and stores key revocation data (HKB) from the key revocation data distribution station 130. A data storage unit 102, a media key calculation unit 103 that decrypts key revocation data with a device key to calculate a media key (Km), a media key (Km) calculated by the media key calculation unit 103, and an encrypted content key And a medium identification number (MID) into a one-way function to generate an authenticator (MAC: Message Authentication Code), and an externally input content with the calculated media key (Km) A content key encrypting unit 105 for encrypting a key, a content encrypting unit 106 for encrypting externally input content with a content key, A secret key storage unit 107 for storing a secret key in a key cryptosystem, and a certificate storage for storing a certificate in which a public key corresponding to the secret key is signed by a certificate authority (hereinafter, referred to as CA). A CRL storage unit 109 for storing a public key certificate revocation list (CRL: Certification Revocation List) showing a list of the latest revoked certificates distributed from the CRL distribution station 140; A signature generation unit 110 for generating a signature. In the copyright protection system according to the present embodiment, an authenticator (MAC) is information used when the reproduction device 200 determines the validity of a content.

  Further, the recording medium 120 has a medium unique number recording area 121 for recording a medium unique number in a non-rewritable area (area indicated by double brackets), and a rewritable area used by the recording apparatus 100 for encryption. A key revocation data recording area 122 for recording key revocation data, an encrypted content key recording area 123 for recording an encrypted content key, an encrypted content recording area 124 for recording encrypted content, 100, a signature recording area 125 for recording the signature generated, a CRL held by the recording device 100, a CRL recording area 126 and a certificate recording area 127 for recording a certificate, and an authentication generated by the authenticator generation unit 104. And an authenticator recording area 128 for recording a child. In the present embodiment, in the recording medium 120, only the medium unique number recording area 121 is written in the non-rewritable area, and the other information is written in the rewritable area. Therefore, in the CPS-2 recording method, the key revocation data can be written in the key revocation data recording area, which is the writable area of the recording medium 120.

  The playback device 200 includes a device key storage unit 201 that stores a device key secretly held by each device, and a medium that calculates the media key (Km) by decrypting the key revocation data read from the recording medium 120 with the device key. The key calculation unit 202, the media key (Km) acquired by the media key calculation unit 202, the medium unique number acquired from the medium unique number recording area 121 of the recording medium 120, and the encrypted content key recording area 123 of the recording medium 120 An authenticator generation unit 203 for generating an authenticator according to a one-way function using three pieces of information of the recorded encrypted content key, and an encrypted content key read from the recording medium 120 with the calculated media key. A content key decryption unit 204 to decrypt, and encrypted content read from the recording medium 120 with the decrypted content key. A content decrypting unit 205 for decrypting, a CA public key storing unit 206 for storing the CA's public key, and verifying the validity of the certificate read from the recording medium 120 using the CA's public key, that is, adding to the certificate A certificate verification unit 207 that verifies the obtained signature, a CRL storage unit 208 that stores the latest CRL obtained from the CRL distribution station 140, and the validity of the CRL read from the recording medium 120 using the public key of the CA. That is, the CRL verifying unit 209 that verifies the signature attached to the CRL, the CRL read from the recording medium 120 and verified for its validity, and the CRL stored in the CRL storage unit 208 are compared with the new and old CRLs. From the recording medium 120 to the CRL comparing / updating unit 210 storing the new CRL in the CRL storing unit 208 and the latest CRL storing in the CRL storing unit 208. A certificate judging unit 211 for judging whether or not the extracted certificate is registered; and a signature verifying unit 212 for verifying the signature read from the recording medium 120 using the certificate read from the recording medium 120. And a switch 213 controlled based on various verification and determination results.

  Further, the playback device 200 includes an authenticator comparing unit 214 that compares the authenticator decrypted by the authenticator generating unit 203 with the authenticator recorded in the authenticator recording area 128 of the recording medium 120. By transmitting the authentication result comparison result to the switch 213, the authenticator comparison unit 214 checks whether an illegal copy has been made via the medium or the content has been written to the recording medium having the correct medium unique number (MID). It is possible to confirm whether or not it has been performed.

As described above, in the CPS-2 recording method used in the copyright protection system according to the present embodiment, the recording device 100 generates an authenticator (MAC) using the medium unique number (MID), By comparing the authenticators on the 200 side, illegal use of the content can be prevented and copyright protection can be achieved.
FIG. 14 is a schematic diagram showing another overall configuration of the CPS-2 recording system used in the copyright protection system.

  The recording device 1400 is different from the recording device 100 shown in FIG. 1 in that the secret key storage unit 107, the certificate storage unit 108, the CRL storage unit 109, and the signature generation unit 110 are omitted. Therefore, in the recording medium 1401, the recording areas of the signature recording area 125, the CRL recording area 126, and the certificate recording area 127 recorded on the recording medium 120 of FIG.

Also, in the playback device 1402, the CA public key storage unit 206, certificate verification unit 207, CRL storage unit 208, CRL verification unit 209, CRL comparison / update unit 210, certificate The configuration is such that the determination unit 211 and the signature verification unit 212 are omitted.
Therefore, in the copyright protection system shown in FIG. 14, the recording apparatus 1400 that illegally records contents on the recording medium 1401 cannot be excluded, but the reproducing apparatus 1402 performs authentication using the medium unique number (MID). By generating a child and comparing the authenticator in the authenticator comparing unit 214, it is possible to eliminate reproduction of illegal content.

  FIG. 2 shows the case where the total number of the playback devices 200 is n, and the playback device 200 of the device key DK_1 has recorded, assuming that the device keys DK_3 and DK_4 of the two playback devices 200 are invalidated. Specific examples of various data stored in the recording medium 120 are shown. Further, in this example, each of the n playback devices 200 has only one unique device key. Note that, in the recording medium 120 shown in this figure, only the medium unique number recording area 120a is a non-rewritable area.

(Medium unique number recording area 120a)
The medium unique number recording area 120a is a non-rewritable area, and a unique number (MID) of the recording medium is recorded for each recording medium 120. In FIG. 2, the medium unique number is represented by eight hexadecimal digits, and the unique number is “6”. The medium unique number (MID) is recorded when the recording medium 120 is manufactured, and “0x” written in the head area of the medium unique number (MID) is a medium unique number having a hexadecimal number. It indicates that The medium unique number illustrated in FIG. 2 has 32 bits.

(Key revocation data recording area 120b)
In the key revocation data recording area 120b, a media key (MK) encrypted with a plurality of device keys (DK) is recorded. Here, E (X, Y) is used as a symbol indicating a cipher text when data Y is encrypted with key data X. The encryption algorithm used can be realized by a known technique, for example, DES encryption or the like is used. The device key held by the playback device n is expressed as DK_n.

  In FIG. 2, since the playback devices 200 of DK_3 and DK_4 are invalidated, data “0” completely unrelated to the media key (MK) is encrypted and recorded in DK_3 and DK_4 held by the respective devices. I have. By generating the media key data in this way, only the devices other than the DK_3 and DK_4 playback devices 200 can share the media key (MK), and the DK_3 and DK_4 playback devices 200 can be eliminated from the system. . It should be noted that other methods may be used for the invalidation of the device. For example, the above-mentioned Patent Document 1 discloses an invalidation method using a tree structure.

(Authenticator recording area 120c)
The authenticator (MAC) generated by the authenticator generation unit 104 of the recording device 100 is recorded in the authenticator recording area 120c.

(Encrypted content key recording area 120d)
The content key (CK) encrypted with the media key (MK) is recorded in the encrypted content key area 120d.

(Encrypted content recording area 120e)
In the encrypted content recording area 120e, a content encrypted with a content key (CK) is recorded.

(Signature recording area 120f)
In the signature recording area 120f, a signature generated for the media key (MK) and the CRL is recorded. Here, Sig (X, Y) is used as a symbol indicating a signature sentence generated using key data X for data Y. The signature generation algorithm used can be realized by a known technique, and for example, an RSA signature or the like is used.

In FIG. 2, a signature sentence generated using the secret key (SK_1) of the device 1 is recorded.
(CRL recording area 120g)
In the CRL recording area 120g, a CRL targeted when the DK_1 reproducing device 200 generates a signature is recorded. The CRL describes the ID of a certificate to be invalidated (here, the certificate of the playback device 200 of DK_3 and DK_4), and a CA signature is given to the ID. Note that the signature of the CA is to guarantee the validity of the CRL. Further, the format of the CRL may be a known format or a format specialized for a certain system. Here, ID_3‖ID_4 indicates that ID digits that uniquely identify the playback device 200 of DK_3 and DK_4 are linked.

(Certificate recording area 120h)
In the certificate recording area 120h, a certificate corresponding to the secret key (SK_1) used when the playback device 200 of DK_1 generates a signature is recorded. The certificate is provided with a certificate ID, a public key (PK_1), and a CA signature for them. The signature of the CA is to guarantee the validity of the certificate. The format of the certificate may be a known format or a format specialized for a certain system.

Next, the operation of each of the recording device 100, the recording medium 120, and the reproducing device 200 in the CPS-2 recording system used in the above copyright protection system will be described.
First, the operation of the recording apparatus 100 will be described. The media key calculation unit 103 reads a device key and key revocation data from the device key storage unit 101 and the key revocation data storage unit 102, respectively, and stores the media key data in the device. A media key (Km) is obtained by decrypting with the key.

The authenticator generation unit 104 generates an authenticator (MAC) by inputting the medium unique number (MID), the media key obtained by the media key calculation unit 103, and the encrypted content key into a one-way function. .
The content key encryption unit 105 encrypts the content key input from the outside with the media key calculated by the media key calculation unit 103. The content encryption unit 106 encrypts the content also input from the outside with the content key input from the outside. The signature generation unit 110 reads the secret key from the secret key storage unit 107 and generates a signature for the media key and the CRL.

Then, the recording device 100 records the stored key revocation data, CRL, certificate, and the generated authenticator, encrypted content key, encrypted content, and signature on the recording medium 120.
The operation of the playback device 200 will be described. The playback device 200 transmits the key revocation data, the medium unique number, the authenticator, the encrypted content key, the encrypted content, the signature, the CRL, and the certificate from the recording medium 120, respectively. read out.

The media key calculation unit 202 obtains a media key (Km) by reading the device key from the device key storage unit 201 and decrypting the read key revocation data with the device key.
The authentication code generation unit 203 decodes the authentication code from the medium unique number (MID) read from the recording medium 120, the media key (Km) obtained from the media key calculation unit 202, and the encrypted content key. The authenticator comparing unit 214 compares the authenticator obtained from the authenticator generating unit 203 with the authenticator read from the recording medium 120. As a result of the comparison, when the authenticators match, the authenticator comparing unit 214 informs the switch 213 of the content reproduction permission.

  The content key decryption unit 204 obtains a content key by decrypting the encrypted content key read from the recording medium 120 with the media key (Km) obtained from the media key calculation unit 202. Further, the content decryption unit 205 obtains the content by decrypting the encrypted content read from the recording medium 120 with the content key obtained by the content key decryption unit 204.

  The certificate verification unit 207 reads the public key of the CA from the CA public key storage unit 206, and verifies the validity of the certificate read from the certificate recording area 127 of the recording medium 120 using the read public key of the CA. I do. When the validity of the certificate is determined to be NG, the switch 213 is opened and the content is not reproduced. On the other hand, when the validity of the certificate is OK, the switch 213 is closed and the content can be reproduced. In the present invention, the switch 213 is closed and the contents are reproduced only when the verification by the certificate verification unit 207, the certificate determination unit 211, the signature verification unit 212, and the authenticator comparison unit 214 described below is all OK. I do.

The CRL verification unit 209 verifies the validity of the CRL read from the CRL recording area 126 of the recording medium 120 using the CA public key read from the CA public key storage unit 206.
The CRL comparing / updating unit 210 reads the CRL from the CRL storage unit 208, and compares the CRL with the CRL read from the CRL verifying unit 209 for new and old. For example, the comparison between new and old uses a version number or the like assigned to the CRL. As a result of the comparison, the CRL determined to be new is stored in the CRL storage unit 208.

The certificate determination unit 211 reads the CRL from the CRL storage unit 208, and determines whether the certificate read from the recording medium 120 has been registered. If it is determined that the content is registered, the switch 213 is opened and the content is not reproduced, while if it is not registered, the switch 213 is closed and the content can be reproduced.
The signature verification unit 212 generates the validity of the signature read from the signature recording area 125 of the recording medium 120 by the certificate read from the recording medium 120, the CRL read by the CRL verification unit 209, and the media key calculation unit 202. Verification is performed using the obtained media key (Km). As a result, when the validity of the signature is NG, the switch 213 is opened and the content is not reproduced, while when the validity of the signature is OK, the switch 213 is closed and the content can be reproduced.

  As described above, in the CPS-2 recording method used in the copyright protection system according to the present embodiment, the recording device 100 generates an authenticator (MAC) using the medium unique number (MID) and At the same time as recording, the reproducing device 200 can confirm the validity of the authenticator (MAC) using the medium unique number (MID). If the authenticator (MAC) is not valid, the playback device 200 cannot play back the content, so that it is possible to prevent the use of the content due to illegal acts such as copying and to protect the copyright. It becomes possible. In addition, the reproducing device 200 can eliminate the unauthorized recording device 100 by using the CRL.

  The above is the description of the CPS-2 recording method used in the copyright protection system according to the present embodiment. Next, the recording device 100 and the copyright protection system according to the present invention will be described.

  FIG. 3 is a block diagram showing a processing unit included in the recording apparatus 100 according to the present invention, and a schematic diagram showing a system for recording contents on the recording medium 120 of the recording apparatus 100. The recording device 100 is, for example, a DVD recorder, and is characterized in that the present invention records contents on a recording medium 120 that can support a plurality of copyright protection recording methods.

  Further, in the present embodiment, the plurality of copyright protection recording systems include a conventional CPRM recording system, the above-described CPS-2 recording system according to the present embodiment, and a Non-CP recording system which does not require copyright protection. Although the description will be made using three recording methods, the recording apparatus 100 according to the present invention is not limited to these three recording methods, and may be applied to a plurality of recording methods using other copyright protection recording methods. Applicable.

The recording device 100 includes a receiving unit 301 that receives content, a control unit 302 that determines a recording method of the content on the recording medium 120, an input unit 303 such as a keyboard provided in the recording device 100 that can be input by a user, and recording of content and the like. And a R / W unit 305 for writing and reading the recording medium 120.
The receiving unit 301 receives the encrypted content 300 via Internet distribution, digital broadcasting, DVD, or the like. Further, the control unit 302 receives, via the R / W unit 305, a recording medium specifying unit 302a that specifies whether the recording medium 120 can support the CPRM recording system, the CPS-2 recording system, or the Non-CP recording system. A source identification unit 302b that determines the type of source as to whether the content is a content subject to copyright protection or not, a CPRM recording method, and a CPS-2 recording method that the recording apparatus 100 selects a copyright protection recording method for the recording medium 120. , Non-CP recording method, and a recording method selection unit 302c that performs conversion between these three recording methods.

The input unit 303 is a keyboard or the like, and inputs to the control unit 302 a selection of a copyright protection recording method for the content from the user of the recording device 100 to the recording medium 120. The storage unit 304 is a hard disk that stores the encrypted content 300 and the like received by the receiving unit 301.
The R / W unit 305 writes content and the like on the recording medium 120 in accordance with the recording system instruction of the copyright protection system from the control unit 302. More specifically, a process of writing information such as content received by the receiving unit 301 to the recording medium 120 according to one or a plurality of recording methods selected from a CPRM recording method, a CPS-2 recording method, and a Non-CP recording method. I do. Further, the R / W unit 305 reads whether the recording medium 120 has key revocation data (HKB) or a medium unique number (MID), and notifies the recording medium specifying unit 302a. Then, the recording method selecting unit 302c determines the recording method of the content on the recording medium 120 according to the information from the recording medium specifying unit 302a and the source specifying unit 302b, and notifies the R / W unit 305. The content is recorded on the recording medium 120 by the recording method.

FIG. 4 is an explanatory diagram of selection of a copyright protection recording method in the recording device 100 according to the present invention. The recording apparatus 100 shown in FIG. 4 is the same as the recording apparatus 100 shown in FIG.
The recording device 100 is a device that selects a recording method of a plurality of contents used in the copyright protection system on the recording medium 41 or the like and records information such as received contents.
In FIG. 4, there are three types of recording media, a recording medium 41 in which medium unique information (MID) and key revocation data (HKB) are written in a non-rewritable area, and a medium unique number ( An MID) is written on the recording medium 42 in which the key revocation data (HKB) is not written, and a recording medium 43 on which neither the medium unique information (MID) nor the key revocation data (HKB) is written.

  For this reason, the recording medium 41 uses a CPRM recording method that requires medium specific information (MID) and key revocation information (HKB), a CPS-2 recording method that requires medium specific information (MID), and copyright protection. The recording medium 42 can correspond to the three copyright protection recording methods of the Non-CP recording method that does not perform the recording, and the CPS-2 recording method that requires medium unique information (MID) and the Non-CP recording method that does not perform the copyright protection. The recording medium 43 can correspond only to the Non-CP recording method, and the two copyright protection recording methods of the -CP recording method can be supported. Therefore, the recording method selection unit 302c of the recording device 100 can select the content recording method according to the type of the recording medium 41 or the like. The case where the recording from the recording device 100 to the recording medium is not possible is indicated as NG.

FIG. 5 is a diagram showing an example of a table for specifying a recording method from the types of the recording medium and the source in the recording apparatus 100 according to the present invention. This table is rewritably stored in the storage unit 304 of the recording apparatus 100.
In FIG. 5, the recording device 100 is a recording medium 41 in a case where the type of the recording medium has a medium unique number (MID) and key revocation data (HKB) written in a non-writable area. When the type is the net distribution, the recording apparatus 100 determines that the recording method of the content to the recording medium 41 is selected from the three recording methods of the CPRM recording method, the CPS-2 recording method, and the Non-CP recording method. Is shown. Thus, the recording apparatus 100 is compatible with a multi-disc capable of recording content according to a plurality of recording methods.

Further, when the recording medium is of the type of the recording medium 43 on which the medium unique information (MID) and the key revocation data (HKB) are not written, since the validity of the content cannot be confirmed on the reproducing apparatus 200 side, the source This indicates that only the Non-CP recording method can be selected regardless of the type.
The recording medium 120 on which the content is recorded by the recording apparatus 100 used in the present embodiment may be a CD-R / RW, a BD (Blu-ray Disc) predicted to be used in the future, or the like, in addition to a DVD. .

  Further, the selection of the copyright protection recording method in the recording apparatus 100 is basically determined by the recording apparatus 100 side, and is also instructed by setting a flag or the like from the content provider side. The format in which the content is recorded on the recording medium 120 in the recording method according to this instruction, and the user of the recording apparatus 100 selects one of the plural recording methods via the input unit 303 such as a keyboard according to the function of the recording apparatus 100. The form in which the selection is made is also conceivable.

  Furthermore, when there are a plurality of copyright protection recording systems, there is a difference in security level between each recording system, and the recording apparatus 100 selects the recording system according to the security level, quality, and the like of the transmitted content. Such cases are also assumed. For example, if the recording apparatus 100 supports a plurality of recording methods, the CPS-2 recording method has a higher security level than the CPRM recording method, and if a higher security level is required when recording contents, the CPS- Recording is performed using two recording methods. Here, the quality of the content includes sound quality, image quality, and the like. For example, in the case of high-definition video content, a predetermined recording method is adopted.

Then, when the recording device 100 that acquires the encrypted content 300 has a plurality of input channels such as broadcast, the Internet, CATV, and DVD (Pre-recorded DVD (sales content) and DVD-RAM (self-recorded content)). In, it is conceivable to select a recording method according to the type of the input channel.
Further, for example, when the recording apparatus 100 according to the present invention supports two types of copyright protection recording methods, ie, the CPRM recording method and the CPS-2 recording method, the recording medium 100 is recorded on the recording medium 120 by the CPRM recording method. It is also possible to convert the existing content into the CPS-2 recording format in the recording format conversion unit 302d and re-record. Further, as described above, the recording apparatus 100 not only converts the content from one recording method to another recording method, but also adds a new recording method while keeping the original recording method to the recording medium 120. Recording is also conceivable. Therefore, by recording one content using both the CPRM recording method and the CPS-2 recording method, the use of the recording medium 120 on which the content has been recorded can be performed even in the playback device 200 that supports only one of the recording methods. It becomes possible to plan.

FIG. 6 is an explanatory diagram of the copyright protection system according to the present embodiment. The server device 600 receives contents from various sources such as Internet distribution, broadcasting, and DVD. The server device 600 is a general server device or a home server device.
In the figure, a recording medium on which content is recorded from the recording device 607 or the like is, for example, a DVD-RAM disc, and can support both the CPRM recording method and the CPS-2 recording method. Therefore, these recording media 610, 611, and 612 become a multi-disc that can support a plurality of copyright protection systems by one. Also, the server device 600 of the content distribution source according to the present embodiment is characterized in that the content is distributed according to the capability of the recording device of the distribution destination and the type of recording medium to be recorded. Conventionally, one recording medium is a recording medium corresponding to a single copyright protection system, and there is no one that realizes moving or copying contents using a multi-disc corresponding to a plurality of copyright protection systems. .

  The server device 600 is connected to three types of recording devices 607, 608, and 609 via a network. The recording device 607 is compatible with CPRM, the recording device 608 is compatible with CPS-2, and the recording device 609 is a recording device that can support both CPRM / CPS-2.

  The server device 600 includes a receiving unit 601 that receives the encrypted content, a storage unit 602 that stores the received content and the like, a device unique information holding unit 603 that holds device unique information written when the server device 600 is manufactured, An encryption unit 604 for encrypting content using device-specific information, key revocation data, and the like; selection for selecting a content encryption method according to the capability of a recording device to which content is distributed and the type of recording medium; And a distribution unit 606 that distributes the encrypted content to the recording device 607 and the like.

  First, when the recording device 607 is compatible with CPRM, the selecting unit 605 selects to distribute the content to be distributed after encrypting it with the session key. Then, the server device 600 decrypts the content encrypted by the device unique information in the encrypting unit 604 by using the device unique information acquired from the device unique information holding unit 603. Next, the server device 600 and the recording device 607 mutually perform authentication processing to share a session key, encrypt the decrypted content with the session key, and transmit the encrypted content to the recording device 607 via the distribution unit 606. I do.

When the recording device 608 is compatible with CPS-2, the selection unit 605 selects to distribute the content to be distributed by encrypting the content with key revocation data (HKB). Then, the server device 600 encrypts the content in the encryption unit 604 based on the key revocation data (HKB) and transmits the content to the recording device 608 via the distribution unit 606.
When the recording device 609 is compatible with CPRM / CPS-2, the selection unit 605 selects to distribute the content to be distributed after encrypting it with a session key or key revocation data (HKB). Then, the server device 600 encrypts the content based on the session key or the key revocation data (HKB) in the encryption unit 604 and transmits the content to the recording device 609 via the distribution unit 606.

As described above, in the copyright protection system according to the present embodiment, when transmitting the encrypted content to the recording device, server device 600 determines the capability of the recording device to which the content is to be distributed or the type of the recording medium. Accordingly, it is possible to select a content encryption method, thereby realizing more efficient content distribution.
Further, according to the copyright protection system according to the present embodiment, not only a conventional single CPS-compatible disc but also a plurality of copyright protection recording scheme-compatible multi-discs that are expected to appear in the future can be used for moving / moving content. Also in copying, it is possible to distribute contents more efficiently while protecting copyright.

FIG. 7 is a diagram showing the relationship between the type of the recording device of the content distribution destination and the content encryption method. This table is stored in the storage unit 602 of the server device 600 in a writable manner. The table shown in FIG. 7 is an example, and the present invention is not limited to this.
In the CPRM compatible recording device (607), a session key is used for the encryption method of the content distributed from the server device 600 to the recording device 607, and in the CPS-2 compatible recording device (608), the session key is used. Key revocation data (HKB) is used for the encryption method of the content to be distributed. In the CPRM / CPS-2 compatible recording device 609, the session key or the encryption method of the content distributed from the server device 600 is used. Indicates that both key revocation data (HKB) can be used. It should be noted that, even in the case of CPS-2, a configuration in which transmission is performed using a session key can be considered.

In FIG. 6, after the recording device 607 or the like reads the medium unique number (MID) written in the non-writable area of the recording medium 610 or the like, the medium unique number is transmitted to the server device 600, A configuration in which the device 600 generates an authenticator (MAC) and transmits it to the recording device 607 or the like.
Further, when the recording device 607 or the like supports a plurality of copyright protection systems, a configuration in which the user of the recording device 607 or the like can specify the encryption mode of the content distributed by the server device 600 may be adopted. Further, the administrator of the server device 600 may specify the information.

Further, when the storage form of the content in the storage unit 602 and the encryption form of the content specified by the recording device 607 are different, the server device 600 re-encrypts the content to be distributed according to the specification from the recording device 607 or the like. Alternatively, a configuration for performing the modification may be used.
Next, an operation of the recording apparatus 100 in selecting a recording method of the copyright protection system will be described. FIG. 8 is a flowchart showing a procedure for selecting a recording method for recording content on the recording medium 120 in the recording apparatus 100 according to the present invention.

  First, the recording device 100 receives the content and distributes the content on the Internet, specifies the recording method from the type of source such as DVD, determines whether the content is copyright protected content, or reads the recording medium and records the content from the type of recording medium 120. It is confirmed whether a recording method for the medium 120 is designated (S801). When this designation is performed (Y in S801), the designated recording method is determined (S806).

  Next, when the designation is not made (N in S801), the recording device 100 confirms whether or not the user has designated the recording method of the content on the recording medium 120 via the input unit 303 such as a keyboard ( S802). If it is designated (Y in S802), the designated recording method is determined (S806). If not specified (N in S802), the recording device 100 determines the type of source such as net distribution, DVD, or broadcast (S803).

  Next, the recording device 100 determines the copyright protection system corresponding to the type of the recording medium 120 by reading the recording medium 120 (S804). Then, the recording apparatus 100 determines the recording method with reference to the table shown in FIG. 5 in order to determine the recording method of the content on the recording medium 120 according to the type of the medium and the type of the source (see FIG. 5). S805).

  Therefore, the recording apparatus 100 of the present invention can select one or a plurality of optimal recording schemes according to the capability of the recording apparatus 100 and the type of the recording medium 120 among the recording schemes of a plurality of copyright protection systems. Thus, the recording apparatus 100 capable of supporting a plurality of copyright protection systems can be provided.

  FIG. 9 is a flowchart showing a procedure when the server device 600 determines an encryption method of content to be distributed to the recording device 607 or the like.

  First, the server device 600 specifies the type of the recording device 607 or the like to which the content is distributed. More specifically, as shown in FIG. 7, it is specified whether the device is compatible with CPRM, CPS-2, or CPRM / CPS-2 (S901).

  Next, the server device 600 determines a content encryption method with reference to the table shown in FIG. 7 (S902). Then, the server device 600 encrypts the content to be distributed according to the determined encryption method (S903), and outputs the distributed content via the distribution unit 606 (S904).

  Therefore, the server device 600, which is the content distribution source, can distribute the content in accordance with the capability of the recording device 607 or the like of the distribution destination, and can cope with a plurality of recording methods, and more efficiently distribute the content. Can be realized.

  FIG. 10 is a reference diagram for explaining unauthorized use in remote playback and copying of content recorded using the CPS-2 recording method, which is the copyright protection recording method according to the present embodiment.

  In FIG. 10, an AVC server 1002 is, for example, a server device at home, and distributes encrypted content to a remote terminal device 1003 wirelessly or the like. Note that FIG. 10A illustrates the normal remote reproduction, and FIG. 10B illustrates the case where the remote reproduction of the content is illegally performed using the unauthorized recording medium 1004 obtained by copying the recording medium 1001 or the like. It is for explanation.

  The recording medium 1001 has a medium unique number (MID), which is a unique number for each recording medium, written in a non-writable area, an authenticator (MAC), a signature, key revocation data (HKB), and content written in a writable area. I have. The AVC server 1002 transmits the medium unique number (MID), the authenticator (MAC), and the signature to the remote terminal device 1003, and the remote terminal device 1003 verifies whether there is any unauthorized use of the content. Also, the remote terminal device 1003 receives the key revocation data (HKB) and the content transmitted from the AVC server 1002, and decrypts and reproduces the content.

  On the other hand, when the content is used by using the recording medium 1004 that has been illegally copied, the medium unique number (MID) at the time of manufacture of each recording medium is usually different. In addition, it is possible to prevent illegal use of contents. However, in FIG. 10B, since the distribution of the medium unique number (MID) is performed by remote reproduction using a radio or the like, the medium unique number (MID) is rewritten to a regular medium unique number on the communication path. May be possible. In such a case, the content sent from the AVC server 1005 to the remote playback terminal 1006 may be used illegally. That is, in the case where the content recorded on the recording medium 1004 by the CPS-2 recording method is used for remote playback at home or the like, an attack that illegally obtains the medium unique number (MID) over the radio can be considered.

  In order to solve such a problem, in this embodiment, a secure authentication channel (SAC) is provided on a communication path to secure the communication path. FIG. 11 is an overall view in the case of performing remote playback and remote recording of content using the CPS-2 recording method according to the present embodiment.

  In FIG. 11A, after an encrypted communication channel (SAC) is established to prevent the medium unique number (MID) shown in FIG. 10B from being rewritten on the communication channel, the medium unique number (MID) is set. MID), an authenticator (MAC), and a signature are transmitted from the AVC server 1102 to the remote playback device 1103.

  FIG. 11B is a diagram illustrating a case where content is transmitted from the PC / AVC server 1105 to the remote recording device 1106. The information corresponding to the medium unique number (MID) of the recording medium is stored in the hard disk 1104. The HDD ID used as the identification number is used. Then, as in the case shown in FIG. 11A, the PC / AVC server 1105 sets the HDD ID, the authenticator (MAC), and the signature to the remote recording device 1106 after setting the communication channel to an encrypted communication channel using SAC or the like. Send to In this case, the authenticator (MAC) is generated in the PC / AVC server 1105 using the HDD ID.

  Therefore, in the present embodiment, by using the encrypted communication channel (SAC), it is possible to safely transmit the HDD ID to the remote recording device 1106 so that the HDD ID is not replaced on the communication channel, and 1106 records the key revocation data (HKB) and the content as they are on the recording medium 1107, reads the medium unique number (MID) from the recording medium 1107, and outputs an authenticator (MAC) corresponding to the medium unique number, and After the signature is generated, the authenticator (MAC) and the signature are recorded on the recording medium 1107. Thus, the remote recording device 1106 needs to perform the verification processing and the generation processing.

  In FIG. 11, it is conceivable to use a PC or PC application ID instead of the HDD ID transmitted from the PC / AVC server 1105 to the remote recording device 1106. Further, in communication in which the remote recording device 1106 separately authenticates the PC / AVC server 1105, it is not necessary to transmit the HDD ID, the authenticator (MAC), and the signature, and further, the recording device such as a DVD double drive. It is needless to say that it is not necessary to use an encrypted communication channel (SAC) when recording is performed in.

  As described above, even when the content is distributed to the remote terminal device 1103 or the like, an unauthorized server device can establish an encrypted communication channel (SAC) by using the encrypted communication channel (SAC) as the communication channel. In addition, it is possible to prevent the rewriting of the medium unique information (MID) and the HDD ID on the communication path, and to safely distribute the content to the remote terminal device 1103 and the remote recording device 1106.

  In the above-described embodiment, the description has been made using the CPRM recording method, the CPS-2 recording method, and the Non-CP recording method as the recording method of the content and the like used in the copyright protection system. The copyright protection recording system that can be used is not limited to this. That is, in the present invention, the recording device 100 can record contents on a recording medium in a manner compatible with a plurality of copyright protection systems.

FIG. 1 is a schematic diagram showing an overall configuration of a CPS-2 recording system used in a copyright protection system used in the present embodiment. FIG. 14 is a diagram illustrating a specific example of various data stored in a recording medium recorded by a reproducing device of a device key DK_1. FIG. 1 is a block diagram illustrating a processing unit included in a recording device, and a schematic diagram illustrating a system for recording content on a recording medium of the recording device. FIG. 4 is an explanatory diagram of selection of a copyright protection recording method in a recording device. FIG. 4 is a diagram illustrating an example of a table for specifying a recording method from types of recording media and a source in the recording apparatus. FIG. 1 is an explanatory diagram of a copyright protection system according to the present embodiment. FIG. 3 is a diagram illustrating a relationship between a type of a recording device of a content distribution destination and a content encryption method. 5 is a flowchart showing a procedure for selecting a recording method of a content on a recording medium in the recording device. 9 is a flowchart illustrating a procedure in a case where a server apparatus determines an encryption method of content to be distributed to a recording apparatus. FIG. 3 is a reference diagram for explaining unauthorized use in remote reproduction and copying of content recorded using the CPS-2 recording method, which is the copyright protection recording method according to the present embodiment. FIG. 2 is an overall view in the case where remote reproduction and remote recording of content using the CPS-2 recording method according to the present embodiment are performed. It is an explanatory view for explaining a conventional key revocation technology. FIG. 11 is an explanatory diagram of a recording device corresponding to a conventional single copyright protection system. FIG. 11 is a schematic diagram illustrating another overall configuration of the CPS-2 recording system used in the copyright protection system.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 100 Recording device 120 Recording medium 130 Key invalidation data distribution station 140 CRL distribution station 200 Playback device 301 Receiving unit 302 Control unit 302a Content specifying unit 302b Source specifying unit 302c Recording method selecting unit 302d Recording method converting unit 303 Input unit 304 Storage unit 305 R / W unit 600 server device 601 reception unit 602 storage unit 603 device-specific information storage unit 604 encryption unit 605 selection unit 606 distribution unit 607 CPRM compatible recording device 608 CPS-2 compatible recording device 609 CPRM / CPS-2 compatible recording Apparatus 610 Recording media 1001 Recording media 1002 AVC server 1003 Remote terminal device 1101 Recording media 1104 Hard disk 1105 PC / AVC server 1106 Remote recording device 1107 Recording media

Claims (19)

A recording device that records content that is a digital work on a recording medium,
Content acquisition means for acquiring content provided from outside;
Content type specifying means for specifying the type of the received content;
Recording medium type specifying means for specifying the type of the recording medium,
Recording method selection for selecting at least one recording method from among a plurality of recording methods based on the type of content specified by the content type specifying means and the type of recording medium specified by the recording medium type specifying means Means,
Recording means for recording the content on the recording medium in accordance with a selected recording method. The content type specifying means specifies, as the type of the content, at least whether the content is a first type provided by a transmission medium or a second type provided by a recording medium. The recording device according to the above. The recording apparatus according to claim 1, wherein the recording medium type specifying unit specifies the type of the recording medium based on a type of information stored in a non-rewritable area of the recording medium in advance. 2. The recording apparatus according to claim 1, wherein the recording method selection unit selects one recording method from a plurality of recording methods corresponding to a method for protecting the copyright of the content. The recording apparatus according to claim 1, wherein the recording method selection unit further selects one recording method from among the plurality of recording methods based on an instruction from a provider that provided the content. . The content includes specification information for specifying one of the plurality of recording methods,
The recording apparatus according to claim 1, wherein the recording method selection unit further selects one recording method from among the plurality of recording methods based on designation information included in the content. The recording apparatus according to claim 1, wherein the recording method selection unit further selects one recording method from the plurality of recording methods based on a user's instruction. The recording apparatus according to claim 1, wherein the recording method selection unit further selects one recording method from the plurality of recording methods based on a security level required for the content. The recording apparatus according to claim 1, wherein the recording method selection unit further selects one recording method from the plurality of recording methods based on the quality of the content. The content acquisition unit has a plurality of input channel units corresponding to the type of data to be acquired,
The recording method selecting means further selects one recording method from among the plurality of recording methods depending on which of the plurality of input channel units the content is acquired from. The recording device according to claim 1. When the first content is recorded on the recording medium in the first recording format, the recording unit records the second content in the second recording format while leaving the first content. The recording apparatus according to claim 1, wherein: A first content is recorded on the recording medium by a first recording method,
The recording device according to claim 1, wherein the recording device further reads the first content from the recording medium, and then records the first content on the recording medium in a second recording format. apparatus. The recording method selection means selects two or more recording methods from among the plurality of recording methods,
The recording apparatus according to claim 1, wherein the recording unit records the content on the recording medium according to two or more selected recording methods. The content acquisition unit transmits the acquired content to the recording unit via a transmission path,
The recording means records the content received via the transmission path on the recording medium,
2. The recording apparatus according to claim 1, wherein the content acquisition unit transmits the encrypted content to the recording unit after encrypting the content according to a recording method adopted by a recording unit serving as a transmission destination. 3. . The recording method includes first and second recording methods corresponding to a method for protecting the copyright of the content,
When the recording means adopts the first recording method, the content acquisition means encrypts the content using a secret key held in advance, and the recording means changes the second recording method. 15. The recording device according to claim 14, wherein, when adopted, the content is encrypted using a secret key obtained from outside. The recording method includes first and second recording methods corresponding to a method for protecting the copyright of the content,
When the acquired content is an encrypted content corresponding to the first recording method, the content acquisition unit re-encrypts the content into an encrypted content corresponding to the second recording method. The recording device according to claim 14, wherein the recording device is transmitted to a recording unit. A recording method for recording a digital work content on a recording medium,
A content acquisition step of acquiring content provided from outside;
A content type identification step of identifying the type of the received content;
A recording medium type specifying step of specifying the type of the recording medium,
Recording method selection for selecting at least one recording method from among a plurality of recording methods based on the content type specified in the content type specifying step and the recording medium type specified in the recording medium type specifying step Steps and
A recording step of recording the content on the recording medium in accordance with a selected recording method. A recording medium recorded by a recording device that records content that is a digital work,
The recording device,
Content acquisition means for acquiring content provided from outside;
Content type specifying means for specifying the type of the received content;
Recording medium type specifying means for specifying the type of the recording medium,
Recording method selection for selecting at least one recording method from among a plurality of recording methods based on the type of content specified by the content type specifying means and the type of recording medium specified by the recording medium type specifying means Means,
Recording means for recording the content on the recording medium in accordance with a selected recording method. A program used for a recording method of recording content that is a digital work on a recording medium,
A content acquisition step of acquiring content provided from outside;
A content type identification step of identifying the type of the received content;
A recording medium type specifying step of specifying the type of the recording medium,
Recording method selection for selecting at least one recording method from among a plurality of recording methods based on the content type specified in the content type specifying step and the recording medium type specified in the recording medium type specifying step Steps and
Recording the content on the recording medium according to a selected recording method.

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