JP2006229277A - Recording and reproducing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the convenience of transmitting/receiving a huge amount of contents while protecting the copyright, in a recording and reproducing system wherein a recording section and a reproducing section are physically separated. <P>SOLUTION: A recording section 101 uses a recording medium 121 with a copyright protection function, to transmit/receive a contents key for encrypting contents to/from a reproduction section 111 physically separated from the recording section 101. Since the reproduction section 111 can use the received contents key, it is not required to always use the recording medium 121 with the copyright protection function at reproduction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording / reproducing system that performs copyright protection by encrypting information signals such as video and audio.

  Since the digitalization of video and audio content has progressed, and the development of computer technology has made it easier to handle digital content, it has become possible to easily duplicate without compromising the quality of the content. Although simple copying in this way is advantageous in terms of user convenience, it is easy to distribute content without paying the copyright holder a reasonable price for the content. It has become a big problem in recent years from the viewpoint.

  Against this background, a technology has been developed that encrypts content when it is copied so that the copied content cannot be reproduced even if copied further. Products that have a copyright protection function such as an SD memory card It has been put into practical use as an applied device.

  Currently, these recording media having a copyright protection function have a disadvantage that the unit price for the capacity is high, and it is expensive to store a large amount of content.

  For these reasons, in recent years, portable players that record encrypted data on a large-capacity hard disk are becoming popular. These portable players directly connect to a device that supplies the content and perform mutual authentication to record the content in an encrypted manner.

  On the other hand, a device with low portability such as a car AV device cannot always be connected to a device that supplies content. In order to play back content on such a device, a recording medium having the above-described copyright protection function is required.

  As described above, since a recording medium having a copyright protection function has a high unit price with respect to capacity, a system for recording and reproducing by combining a recording medium having a copyright protection function and a recording medium with a low capacity unit price has been proposed. (For example, refer to Patent Document 1).

  The configuration and operation of a recording / reproducing system that performs recording / reproduction by combining a recording medium having a copyright protection function and a recording medium having no copyright protection function will be described below with reference to FIG.

  FIG. 4 is a block diagram showing a configuration of a conventional recording / reproducing system. In the figure, a recording medium 121 is a recording medium having a copyright protection function, and a recording medium 131 is a recording medium having no copyright protection function. The recording unit 401 uses the content key generated by the content key generation unit 104 to encrypt the content by the content encryption unit 103 and records it on the recording medium 131. The content key is confirmed by mutual authentication between the authentication unit 102 of the recording unit 401 and the authentication unit 122 of the recording medium 121 by mutual authentication. After the confirmation, the content key is recorded in the recording unit 123. To do.

On the other hand, in the reproducing unit 411, the mutual authentication between the authenticating unit 112 of the reproducing unit 411 and the authenticating unit 122 of the recording medium 121 confirms that they are legitimate devices, and after confirmation, they are recorded in the recording unit 123 Read the content key. Using this content key, the encrypted content read from the recording medium 131 is read, the content decrypting unit 114 decrypts it, and the content is output.
JP 2002-368732 A

  In the recording / reproducing system described above, it is necessary to use a combination of the recording medium 121 having the copyright protection function and the recording medium 131 having no copyright protection function. If there are a plurality of combinations, the reproduction cannot be performed if the combinations are incorrect. In addition, if a recording medium having a copyright protection function is forgotten or lost, playback becomes impossible.

  An object of the present invention is to provide a recording / reproducing system that is convenient for the user while protecting the copyright for a low-portability device in consideration of the decrease in the convenience of the conventional user. And

  In order to achieve the above object, a recording / reproducing system according to a first aspect of the present invention includes a recording unit for encrypting and recording digital content using a content key, and a content encrypted using the content key. A recording / reproducing system comprising a reproducing unit for decrypting and reproducing, a first recording medium for recording a content key for encrypting the content, and a second recording medium for recording the encrypted content, The recording unit authenticates the validity of the first recording medium with content encryption key generating means for generating a content key for encrypting the content, and writes the content key to the first recording medium. Content that encrypts the content using the authentication means and the content key, and records the encrypted content on the second recording medium Encoding means, and the reproducing unit authenticates the validity of the first recording medium and reads out a content key recorded on the first recording medium, and the content Content key storage means for storing a key, and content decryption means for reading the encrypted content from the second recording medium and decrypting the content using the content key stored in the content key storage means And the first recording medium authenticates the validity of the recording unit and the reproducing unit, and reads and writes the content key between the reproducing unit and the recording unit. And a recording means for recording the content key.

  The recording / reproducing system of the second invention of the present invention is characterized in that, in the first invention, a random value generated by the content key generating means is used as the content key.

  The recording / reproducing system according to a third aspect of the present invention is characterized in that, in the first aspect, the number of times the content key is written from the recording unit to the first recording medium is limited to a predetermined number. Is.

  The recording / reproducing system according to a fourth aspect of the present invention is the recording / reproducing system according to the first aspect, wherein the reproducing unit erases the content key from the first recording medium after reading the content key from the first recording medium. It is characterized by.

  According to a fifth aspect of the present invention, there is provided a recording / reproducing system according to the first aspect, wherein the reproducing unit rewrites the content key read from the first recording medium into the first recording medium and stores it in the reproducing unit. The content key that has been deleted is erased.

  The recording / reproducing system according to a sixth aspect of the present invention is the recording / reproducing system according to the third aspect, wherein the recording unit writes to the first recording medium when the content key recorded on the first recording medium is erased. The number of content keys from which the count is erased is subtracted.

  According to a seventh aspect of the present invention, there is provided a recording / reproducing system according to the first aspect, wherein the second recording medium is any one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. .

  According to an eighth aspect of the present invention, there is provided a recording / reproducing system according to the first aspect, wherein the first recording medium and the second recording medium are configured as one medium.

  According to a ninth aspect of the present invention, in the first aspect, the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using communication means. It is a feature.

  According to a tenth aspect of the present invention, in the first aspect, the reproducing unit has a third recording medium, and the encrypted content recorded on the second recording medium is duplicated and recorded. At the time of reproduction, the content reproduced from the third recording medium is decrypted.

  A recording / reproducing system according to an eleventh aspect of the present invention includes a recording unit that encrypts and records digital content using a content key, and a reproducing unit that decrypts and reproduces the content encrypted using the content key. A recording / reproducing system comprising a first recording medium for recording a content key for encrypting content and a second recording medium for recording the encrypted content, wherein the reproducing unit encrypts the content A content key generating and storing means for storing the generated content key, authenticating the validity of the first recording medium, and writing the content key to the first recording medium And an authentication unit that reads encrypted content from the second recording medium and decrypts the content using the content key. A second decryption unit that authenticates the validity of the first recording medium and reads a content key recorded on the first recording medium; and Content encryption means for encrypting content using a content key and recording the encrypted content on the second recording medium, wherein the first recording medium includes the recording unit and the playback A third authentication unit that authenticates the legitimacy of the content unit and reads / writes the content key between the playback unit and the recording unit, and a recording unit that records the content key. Is.

  The recording / reproducing system of the twelfth aspect of the present invention is characterized in that, in the eleventh aspect, the ID of the reproducing unit is used as the content key.

  A recording / reproducing system according to a thirteenth aspect of the present invention is characterized in that, in the eleventh aspect, a random value generated by the content key generating / storing means is used as the content key.

  A recording / reproducing system according to a fourteenth aspect of the present invention is characterized in that, in the eleventh aspect, the number of times the content key is written from the reproducing unit to the first recording medium is limited to a predetermined number of times. Is.

  According to a fifteenth aspect of the present invention, in the eleventh aspect, the recording unit reads the content key from the first recording medium and then erases the content key from the first recording medium. It is characterized by.

  In the recording / playback system according to the sixteenth aspect of the present invention, in the eleventh aspect, the recording unit writes the content key read from the first recording medium back to the first recording medium and stores it in the recording unit. The content key that has been deleted is erased.

  According to a seventeenth aspect of the present invention, in the fourteenth aspect, when the reproducing unit erases the content key recorded on the first recording medium, the recording on the first recording medium is performed. The number of content keys from which the count is erased is subtracted.

  According to an eighteenth aspect of the present invention, in the eleventh aspect, the recording unit has a content key storage means for storing a content key read from the first recording medium. is there.

  According to a nineteenth aspect of the present invention, in the eleventh aspect, the second recording medium is any one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. .

  According to a twentieth aspect of the present invention, in the eleventh aspect of the present invention, the first recording medium and the second recording medium are configured as one medium.

  According to a twenty-first aspect of the present invention, in the eleventh aspect, the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using communication means. It is a feature.

  The recording / reproducing system according to a twenty-second aspect of the present invention is the recording / reproducing system according to the eleventh aspect, wherein the reproducing unit has a third recording medium and duplicates and records the encrypted content recorded on the second recording medium. At the time of reproduction, the content reproduced from the third recording medium is decrypted.

  A recording / reproducing system according to a twenty-third aspect of the present invention includes a recording unit that encrypts and records digital content using a content key, and a reproducing unit that decrypts and reproduces content encrypted using the content key A recording / reproducing system comprising a first recording medium for recording a unique key for encrypting a content key, and a second recording medium for recording the encrypted content and the encrypted content key, The reproduction unit generates a unique key unique to the reproduction unit, authenticates the unique key generation storage unit that stores the generated unique key, and the validity of the first recording medium, and stores the authenticity on the first recording medium. A first authentication means for writing the unique key, and a content key decryption that reads the encrypted content key from the second storage medium and decrypts the content key using the unique key. And a content decrypting unit that reads the encrypted content from the second recording medium and decrypts the content using the content key, and the recording unit encrypts the content. A content key generating means for generating a key, a content encryption means for encrypting the content using the content key, and recording the encrypted content on the second recording medium, and a validity of the first recording medium A second authentication unit that reads the unique key recorded on the first recording medium, encrypts the content key using the unique key, and encrypts the content key on the second recording medium. Content key encryption means for recording the content key, and the first recording medium authenticates the validity of the recording unit and the playback unit, and A third authentication unit for reading and writing said unique key with the raw unit and the recording unit, and is characterized in that it has a recording means for recording the unique key.

  The recording / reproducing system of the twenty-fourth aspect of the present invention is characterized in that, in the twenty-third aspect, the ID of the reproducing unit is used as the unique key.

  According to a twenty-fifth aspect of the present invention, in the twenty-third aspect, the random value generated by the unique key generation / storage means is used as the unique key.

  The recording / reproducing system according to a twenty-sixth aspect of the present invention is characterized in that, in the twenty-third aspect, the number of times the fixed key is written from the reproducing unit to the first recording medium is limited to a predetermined number. Is.

  According to a twenty-seventh aspect of the present invention, in the twenty-third aspect, the recording unit reads the fixed key from the first recording medium and then erases the fixed key from the first recording medium. It is characterized by.

  In the recording / playback system according to the twenty-eighth aspect of the present invention, in the twenty-third aspect, the recording unit writes the unique key read from the first recording medium back to the first recording medium and stores it in the recording unit. The unique key that has been deleted is erased.

  The recording / reproducing system according to a twenty-ninth aspect of the present invention is the recording and reproducing system according to the twenty-sixth aspect, wherein the reproducing unit writes to the first recording medium when the unique key recorded on the first recording medium is erased. The number of unique keys from which the count is deleted is subtracted.

  The recording / reproducing system according to a thirtieth aspect of the present invention is characterized in that, in the twenty-third aspect, the recording section has a unique key storage means for storing a unique key read from the first recording medium. is there.

  In the recording / reproducing system according to the thirty-first aspect of the present invention, in the twenty-third aspect, the second recording medium is any one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. The recording / reproducing system described in 1.

  A recording / reproducing system according to a thirty-second invention of the present invention is characterized in that, in the twenty-third invention, the first recording medium and the second recording medium are configured as one medium.

  According to a thirty-third aspect of the present invention, in the twenty-third aspect, the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using communication means. It is a feature.

  The recording / playback system according to a thirty-fourth aspect of the present invention is the recording and reproducing system according to the twenty-third aspect, wherein the encrypted content key to be recorded on the second recording medium is recorded so as to be incorporated into the corresponding encrypted content file. It is characterized by doing.

  The recording / reproducing system of the thirty-fifth aspect of the present invention is the recording and reproducing system according to the twenty-third aspect, wherein the content key is encrypted with a plurality of unique keys corresponding to a plurality of reproducing units, and the plurality of encrypted content keys are It records on the recording medium of this.

  The recording / reproducing system of the thirty-sixth aspect of the present invention is the recording / reproducing system according to the twenty-third aspect, wherein the reproducing unit has a third recording medium, the encrypted content recorded on the second recording medium and the encrypted content The recording / reproducing system according to claim 23, wherein the content key is copied and recorded, and the content and content key reproduced from the third recording medium are decrypted and reproduced at the time of reproduction.

  According to the present invention, a recording medium having a copyright protection function becomes unnecessary at the time of reproduction, and it is possible to provide a recording / reproduction system that is convenient for the user while protecting the copyright in a device having low portability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a recording / reproducing system according to Embodiment 1 of the present invention. First, the configuration of the recording / reproducing system of the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the recording / reproducing system according to the first embodiment includes a recording unit 101 that encrypts and records content in a digital format using a content key, and decrypts the content encrypted using the content key. A playback unit 111 for playback, a recording medium 121 for recording a content key for encrypting the content, and a recording medium 131 for recording the encrypted content are included.

  The recording unit 101 includes a content encryption key generation unit 104 that generates a content key for encrypting content, an authentication unit 102 that authenticates the validity of the recording medium 121 and writes the content key to the recording medium 121, and the content The content encryption unit 103 is configured to encrypt the content using the key and to record the encrypted content on the recording medium 131.

  In addition, the reproducing unit 111 authenticates the validity of the recording medium 121, reads the content key recorded on the recording medium 121, the content key storage unit 116 that stores the content key, and the recording medium 131. The content decrypting unit 114 reads the encrypted content and decrypts the content using the content key stored in the content key storage unit 116.

  The recording medium 121 authenticates the legitimacy of the recording unit 101 and the reproducing unit 111 and records the content key, and an authentication unit 122 that reads and writes the content key between the reproducing unit 111 and the recording unit 101. Recording unit 123. That is, the recording medium 121 is a recording medium having a copyright protection function.

  Next, the operation will be described. The content to be recorded is encrypted by the content encryption unit 103 using the content key generated by the content key generation unit 104 and recorded on the recording medium 131. On the other hand, the content key used for encryption is recorded on the recording medium 121 through the authentication unit 102. Before recording the content key on the recording medium 121, it is mutually authenticated that the recording unit 101 and the recording medium 121 are valid devices.

  On the other hand, the playback unit 111 first authenticates with the recording medium 121 that the devices are mutually valid, reads the content key recorded thereafter, and stores it in the content key storage unit 116. Then, the encrypted content is read from the recording medium 131, and is decrypted by the content decryption unit 114 using the content key stored in the content key storage unit 116.

  As described above, since the content key has been moved to the playback unit 111 in advance, the recording medium 121 having a copyright protection function is not required during playback.

  Note that the content key generated by the content key generation unit 104 of the recording unit 101 may be an ID unique to the recording unit 101, or a random value may be generated and used.

  Further, the number of recordings of the content key from the recording unit 101 to the recording medium 121 may be limited to a predetermined number.

  Further, the reproducing unit 111 may erase the content key from the recording medium 121 after reading the content key from the recording medium 121.

  Further, the reproducing unit 111 may write the content key read from the recording medium 121 back to the recording medium 121 again and erase the content key stored in the content key storage unit 116.

  Further, when managing the number of times the content key is recorded by the recording unit 101, if the content key recorded in the storage medium 121 is deleted, the number of times the content key is recorded may be subtracted.

  By managing content keys like these, it is possible to control copyright.

  The recording medium 131 may be any medium such as an optical disk, a magneto-optical disk, a hard disk, or a semiconductor memory that can transfer contents.

  In the present embodiment, the recording medium 121 and the recording medium 131 are described as separate media. However, as long as they have the same function, they may be an integrated medium.

  In this embodiment, the content encrypted through the recording medium 131 is transferred from the recording unit 101 to the reproducing unit 111, but may be transferred using communication.

  Further, a recording medium is built in the reproducing unit 111, and the content recorded on the recording medium 131 is temporarily copied to the built-in recording medium, then read from the built-in recording medium, decoded by the content decoding unit 114, and reproduced. May be.

(Embodiment 2)
FIG. 2 is a block diagram showing a configuration of a recording / reproducing system according to Embodiment 2 of the present invention. First, the configuration of the recording / reproducing system of the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, the recording / playback system according to the second embodiment includes a recording unit 201 that encrypts and records content in a digital format using a content key, and decrypts the content encrypted using the content key. A playback unit 211 for playback, a recording medium 121 for recording a content key for encrypting the content, and a recording medium 131 for recording the encrypted content are configured.

  The playback unit 211 generates a content key for encrypting the content, authenticates the validity of the content key generation storage unit 113 that stores the generated content key, and the recording medium 121, and stores the content key in the recording medium 121. An authentication unit 112 for writing and a content decrypting unit 114 for reading the encrypted content from the recording medium 131 and decrypting the content using the content key.

  The recording unit 201 authenticates the validity of the recording medium 121, encrypts the content using the authentication unit 102 that reads the content key recorded on the recording medium 121, and the content key, and encrypts the content on the recording medium 131. The content encryption unit 103 records the converted content.

  The recording medium 121 authenticates the legitimacy of the recording unit 201 and the reproducing unit 211, and records the content key and an authentication unit 122 that reads and writes the content key between the reproducing unit 211 and the recording unit 201. Recording unit 123. That is, the recording medium 121 is a recording medium having a copyright protection function.

  Next, the operation will be described. First, a content key used for content encryption is generated in the content key generation storage unit 113 of the playback unit 211 and recorded in the recording medium 121 through the authentication unit 112. Before recording the content key on the recording medium 121, it is mutually authenticated that the reproducing unit 211 and the recording medium 121 are valid devices.

  The content to be recorded is encrypted by the content encryption unit 103 of the recording unit 201 using the content key read from the recording medium 121 and recorded on the recording medium 131. Before reading the content key from the recording medium 121, it is mutually authenticated that the recording unit 201 and the recording medium 121 are valid devices.

  The playback unit 211 reads the encrypted content from the recording medium 131, and the content decryption unit 114 decrypts it using the content key stored in the content key generation storage unit 113.

  As described above, the content key is generated and stored in the playback unit 211, and the recording medium 121 having the copyright protection function is not required during playback.

  Note that the content key generated by the content key generation storage unit 113 of the playback unit 211 may be an ID unique to the playback unit, or a random value may be generated and used.

  Further, the number of recordings of the content key from the reproducing unit 211 to the recording medium 121 may be limited to a predetermined number.

  The recording unit 201 may delete the content key from the recording medium 121 after reading the content key from the recording medium 121.

  Further, the recording unit 201 may write back the content key read from the recording medium 121 to the recording medium 121 again, and erase the content key stored in the recording unit 201.

  Further, when the content key recorded on the storage medium 121 is erased, the playback unit 211 may subtract the number of times the content key has been erased.

  By managing content keys like these, it is possible to control copyright.

  The recording medium 131 may be any medium such as an optical disk, a magneto-optical disk, a hard disk, or a semiconductor memory that can transfer contents.

  In the present embodiment, the recording medium 121 and the recording medium 131 are described as separate media. However, as long as they have the same function, they may be an integrated medium.

  In this embodiment, the encrypted content is transferred from the recording unit 201 to the reproduction unit 211 via the recording medium 131, but may be transferred using communication.

  In addition, a recording medium is built in the reproducing unit 211, and the content recorded on the recording medium 131 is temporarily copied to the built-in recording medium, then read from the built-in recording medium, decoded by the content decoding unit 114, and reproduced. May be.

(Embodiment 3)
FIG. 3 is a block diagram showing a configuration of a recording / reproducing system according to Embodiment 3 of the present invention. First, the configuration of the recording / reproducing system of the present embodiment will be described with reference to FIG.

  As shown in FIG. 3, the recording / reproducing system according to the third embodiment includes a recording unit 301 that encrypts and records digital content using a content key, and uses the content key to encrypt the content. The reproduction unit 311 for decrypting and reproducing, the recording medium 121 for recording the unique key for encrypting the content key, and the recording medium 131 for recording the encrypted content and the encrypted content key.

  The playback unit 311 generates a unique key unique to the playback unit 311, authenticates the unique key generation storage unit 113 that stores the generated unique key, and the recording medium 121. An authentication unit 112 for writing, a content key encrypted from the storage medium 131, a content key decryption unit 115 for decrypting the content key using the unique key, and a content encrypted from the recording medium 115 are read out The content decrypting unit 114 decrypts the content using the content key.

  The recording unit 301 includes a content key generation unit 104 that generates a content key for encrypting content, and a content encryption unit 103 that encrypts the content using the content key and records the encrypted content on the recording medium 131. And authenticating the authenticity of the recording medium 121 and reading the unique key recorded in the recording medium 121, and encrypting the content key using the unique key and storing the encrypted content in the recording medium 131 The content key encryption unit 105 records the content key.

  The recording medium 121 authenticates the authenticity of the recording unit 301 and the reproducing unit 311 and records the content key, and an authentication unit 122 that reads and writes the content key between the reproducing unit 111 and the recording unit 301. Recording unit 123. That is, the recording medium 121 is a recording medium having a copyright protection function.

  Next, the operation will be described. First, a unique key used for encrypting the content key is generated in the unique key generation / storage unit 113 of the playback unit 311 and is recorded on the recording medium 121 through the authentication unit 112. Before recording the content key on the recording medium 121, it is mutually authenticated that the reproducing unit 311 and the recording medium 121 are valid devices.

  In addition, the recording unit 301 mutually authenticates that the recording medium 121 is a legitimate device, and reads the unique key recorded thereafter.

  The content to be recorded is encrypted by the content encryption unit 103 using the content key generated by the content key generation unit 104 and recorded on the recording medium 131. The content key is encrypted using the unique key and recorded on the recording medium 131.

  The reproduction unit 311 first reads the encrypted content key from the recording medium 131, and the content key decryption unit 115 decrypts the content key. Then, the encrypted content is read from the recording medium 131 and is decrypted by the content decrypting unit 114 with the decrypted content key.

  In this way, since the content key has been moved to the playback unit 311 in advance, the recording medium 121 having a copyright protection function is not required during playback.

  Note that the unique key generated by the unique key generation / storage unit 113 of the playback unit 311 may be an ID unique to the playback unit 311 or a random value may be generated and used.

  Further, the number of recordings of the unique key from the reproducing unit 311 to the recording medium 121 may be limited to a predetermined number.

  The recording unit 301 may delete the content key from the recording medium 121 after reading the unique key from the recording medium 121.

  Further, the recording unit 301 may write back the unique key read from the recording medium 121 to the recording medium 121 again and erase the unique key stored in the recording unit 301.

  Further, when the unique key recorded in the storage medium 121 is erased, the reproducing unit 311 may subtract the number of unique key recordings by the number of erased.

  By managing content keys like these, it is possible to control copyright.

  The recording medium 131 may be any medium such as an optical disk, a magneto-optical disk, a hard disk, or a semiconductor memory that can transfer contents.

  In the present embodiment, the recording medium 121 and the recording medium 131 are described as separate media. However, as long as they have the same function, they may be an integrated medium.

  In this embodiment, the encrypted content is transferred from the recording unit 301 to the playback unit 311 via the recording medium 131, but may be transferred using communication.

  Further, an encrypted content key to be recorded on the recording medium 131 may be recorded so as to be incorporated into the corresponding content file.

  Alternatively, the content key may be encrypted with each unique key corresponding to a plurality of playback units, and each of these encrypted content keys may be recorded on the recording medium 131.

  Further, a recording medium is built in the playback unit 311, and the content and content key recorded on the recording medium 131 are once copied to the built-in recording medium, then read from the built-in recording medium, and decrypted by the content decryption unit 114. You can play it.

  The recording / reproducing system according to the present invention is useful for a device that records and reproduces content while protecting the copyright in a recording / reproducing system in which a recording unit and a reproducing unit are physically separated.

1 is a block diagram showing a configuration of a recording / reproducing system in Embodiment 1 of the present invention. The block diagram which shows the structure of the recording / reproducing system in Embodiment 2 The block diagram which shows the structure of the recording / reproducing system in Embodiment 3 Block diagram showing the configuration of a conventional recording / reproducing system

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Recording part 102 Authentication part 103 Content encryption part 104 Content key generation part 105 Content key encryption part 111 Playback part 112 Authentication part 113 Content key generation storage part 114 Content decryption part 115 Content key decryption part 116 Content key storage part 121 recording medium 122 recording unit 131 recording medium

Claims (36)

A recording unit that encrypts and records content in digital format using the content key, a playback unit that decrypts and plays back the content encrypted using the content key, and a content key for recording the content key for encrypting the content A recording / reproducing system comprising a first recording medium and a second recording medium for recording encrypted content,
The recording unit authenticates the validity of the first recording medium with content encryption key generating means for generating a content key for encrypting content, and writes the content key to the first recording medium. And authenticating the content using the content key, and content encryption means for recording the encrypted content on the second recording medium,
The reproduction unit authenticates the validity of the first recording medium, and reads out a content key recorded on the first recording medium, and a content key storage unit that stores the content key And content decrypting means for reading the encrypted content from the second recording medium and decrypting the content using the content key stored in the content key storage means,
The first recording medium authenticates the validity of the recording unit and the reproducing unit, and reads and writes the content key between the reproducing unit and the recording unit, and the content And a recording / reproducing system for recording the key. The recording / reproducing system according to claim 1, wherein a random value generated by the content key generation unit is used as a content key. The recording / reproducing system according to claim 1, wherein the number of times the content key is written from the recording unit to the first recording medium is limited to a predetermined number of times. The recording / reproducing system according to claim 1, wherein the reproducing unit erases the content key from the first recording medium after reading the content key from the first recording medium. 2. The reproduction unit according to claim 1, wherein the content key read from the first recording medium is written back to the first recording medium again, and the content key stored in the reproduction unit is erased. The recording / reproducing system described in 1. When the content key recorded on the first recording medium is erased, the recording unit subtracts the number of times of writing the content key to the first recording medium by the number of content keys erased. The recording / reproducing system according to claim 3. 2. The recording / reproducing system according to claim 1, wherein the second recording medium is one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. The recording / reproducing system according to claim 1, wherein the first recording medium and the second recording medium are configured as one medium. 2. The recording / reproducing system according to claim 1, wherein the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using a communication unit. The playback unit has a third recording medium, duplicates and records the encrypted content recorded on the second recording medium, and decrypts the content played back from the third recording medium during playback. The recording / reproducing system according to claim 1. A recording unit that encrypts and records content in a digital format using the content key; a playback unit that decrypts and plays back the content encrypted using the content key; and a content key that encrypts the content. A recording / reproducing system comprising one recording medium and a second recording medium for recording encrypted content,
The playback unit generates a content key for encrypting the content, authenticates the validity of the content key generation and storage means for storing the generated content key, and the first recording medium, and the first recording medium A first authentication unit that writes the content key to the content, and a content decrypting unit that reads the encrypted content from the second recording medium and decrypts the content using the content key,
The recording unit authenticates the legitimacy of the first recording medium, and encrypts content using the second authentication unit that reads the content key recorded on the first recording medium, and the content key. And content encryption means for recording the encrypted content on the second recording medium,
The first recording medium authenticates the validity of the recording unit and the reproducing unit, and reads and writes the content key between the reproducing unit and the recording unit, and the content And a recording / reproducing system for recording the key. 12. The recording / reproducing system according to claim 11, wherein an ID of the reproducing unit is used as a content key. 12. The recording / reproducing system according to claim 11, wherein a random value generated by the content key generation / storage means is used as the content key. 12. The recording / reproducing system according to claim 11, wherein the number of times the content key is written from the reproducing unit to the first recording medium is limited to a predetermined number. The recording / reproducing system according to claim 11, wherein the recording unit erases the content key from the first recording medium after reading the content key from the first recording medium. 12. The recording unit according to claim 11, wherein the content key read from the first recording medium is written back to the first recording medium again, and the content key stored in the recording unit is erased. The recording / reproducing system described in 1. When the content key recorded on the first recording medium is erased, the reproducing unit subtracts the number of times of writing to the first recording medium by the number of content keys erased. The recording / reproducing system according to claim 14. The recording / reproducing system according to claim 11, wherein the recording unit includes a content key storage unit that stores a content key read from the first recording medium. 12. The recording / reproducing system according to claim 11, wherein the second recording medium is any one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. 12. The recording / reproducing system according to claim 11, wherein the first recording medium and the second recording medium are configured as one medium. 12. The recording / reproducing system according to claim 11, wherein the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using a communication unit. The reproduction unit has a third recording medium, duplicates and records the encrypted content recorded on the second recording medium, and decrypts the content reproduced from the third recording medium during reproduction. The recording / reproducing system according to claim 11. A recording unit that encrypts and records content in digital format using the content key, a playback unit that decrypts and plays back the content encrypted using the content key, and a unique key for encrypting the content key A recording / reproducing system comprising a first recording medium and a second recording medium for recording the encrypted content and the encrypted content key,
The reproduction unit generates a unique key unique to the reproduction unit, authenticates the unique key generation storage unit that stores the generated unique key, and the validity of the first recording medium, and stores the authenticity on the first recording medium. First authentication means for writing the unique key, content key decryption means for reading the encrypted content key from the second storage medium, and decrypting the content key using the unique key, and the second Content decrypting means for reading the encrypted content from the recording medium and decrypting the content using the content key,
The recording unit includes: a content key generating unit that generates a content key for encrypting content; and content encryption for encrypting the content using the content key and recording the encrypted content on the second recording medium Means for authenticating the authenticity of the first recording medium, reading the unique key recorded on the first recording medium, and encrypting the content key using the unique key And content key encryption means for recording the encrypted content key on the second recording medium,
The first recording medium authenticates the validity of the recording unit and the reproducing unit, and reads and writes the unique key between the reproducing unit and the recording unit, and the unique recording medium. And a recording / reproducing system for recording the key. 24. The recording / reproducing system according to claim 23, wherein an ID of the reproducing unit is used as the unique key. 24. The recording / reproducing system according to claim 23, wherein a random value generated by the unique key generation / storage means is used as the unique key. 24. The recording / reproducing system according to claim 23, wherein the number of times the fixed key is written from the reproducing unit to the first recording medium is limited to a predetermined number. The recording / reproducing system according to claim 23, wherein the recording unit erases the fixed key from the first recording medium after reading the fixed key from the first recording medium. The recording unit, wherein the unique key read from the first recording medium is written back to the first recording medium again, and the unique key stored in the recording unit is erased. 24. The recording / reproducing system according to 23. When the reproducing unit erases the unique key recorded on the first recording medium, the reproducing unit subtracts the number of times of writing to the first recording medium by the number of unique keys erased. The recording / reproducing system according to claim 26. The recording / reproducing system according to claim 23, wherein the recording unit includes a unique key storage unit that stores a unique key read from the first recording medium. 24. The recording / reproducing system according to claim 23, wherein the second recording medium is one of an optical disk, a magneto-optical disk, a hard disk, and a semiconductor memory. The recording / reproducing system according to claim 23, wherein the first recording medium and the second recording medium are configured as one medium. 24. The recording / reproducing system according to claim 23, wherein the encrypted content recorded on the second recording medium is transmitted from the recording unit to the reproducing unit using a communication unit. 24. The recording / reproducing system according to claim 23, wherein an encrypted content key to be recorded on the second recording medium is recorded so as to be incorporated into a corresponding encrypted content file. The recording / reproducing system according to claim 23, wherein a content key is encrypted with a plurality of unique keys corresponding to a plurality of reproducing units, and the plurality of encrypted content keys are recorded on a second recording medium. . The reproduction unit has a third recording medium, duplicates and records the encrypted content and the encrypted content key recorded on the second recording medium, and reproduces from the third recording medium at the time of reproduction The recording / playback system according to claim 23, wherein the content and the content key are decrypted and played back.

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