JP2007128278A - Content management system, content management method, and program and recording medium used for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To copy a content to other equipment while keeping copy-once spirit. <P>SOLUTION: The content 1 imposed with copy-at-once restriction is received and acquired, it is recorded in an HDD 7, and the content format-converted for the portable content reproduction equipment 17 is recorded in the portable content reproduction equipment 17 through a bridge medium 11 by the copy. At that time, an encryption key 15 is produced from the content recorded in the bridge medium 11, an original content 1a recorded in a recording/reproducing device 5 by use of the encryption key 15 is encrypted to produce an encryption content 3. The original content 1a is deleted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to content management technology, and more particularly to management technology related to copying of digital content.

  For example, content sent by digital broadcasting can generally be copied only once. Therefore, once the broadcast content is recorded in a storage device such as an HDD, the content cannot be copied to another device and can only be moved.

  As a well-known technique in a system for managing contents, a technique for acquiring a license key of contents from an external license server via the Internet (Patent Document 1), acquiring one or a plurality of licenses, and using a license server at home There are those that manage it (Patent Document 2) and those that set a certain ID in the home, manage the ID, and allow copying only those distributed with that ID (Patent Document 3).

JP 2002-358387 A JP 2004-303111 A JP 2004-328517 A

  As described above, in the conventional technique, the content recorded from the digital broadcast cannot be copied and can only be moved. In addition, the method for obtaining the license key from the outside requires connection to the Internet, the point where a license server or ID management server must be started up in the home, and the point where license key and ID must be managed. There is a problem that complicated processing is required.

  In addition, the method of generating content for mobile devices and generating the encryption key from the content requires that the mobile content must be moved each time the content is taken out to the mobile device, and is played back on the recording device. However, there is a problem that both the original content (encrypted) and the mobile content must be held in the recording device in the recording device.

  An object of the present invention is to copy content to other devices while protecting the spirit of copy-once, which is a DRM for digital broadcasting.

  In terrestrial digital broadcasting and BS digital broadcasting, it is allowed to copy the content to be broadcast only once (copy once). Therefore, if the broadcast content is recorded on the recording device, it can only be moved from that recording device. However, since mobile devices have low functionality, the quality of content must be reduced when moving content to mobile devices. Therefore, if the content recorded on the mobile device can be taken out while protecting the spirit of this copy-once, and the content stored on the mobile device is deleted, the high quality stored on the original recording device Make the content playable.

  Record content for mobile devices on an SD card or other bridge media. In order to play back on a mobile device, a bridge medium in which mobile content is recorded may be inserted into the mobile device. This eliminates the need to move mobile content from the recording device to the mobile device. In addition, content for mobile devices recorded on bridge media can be prevented from being illegally copied by using the DRM function of the bridge media itself to prevent copying to other devices.

  In this patent, when content recorded from a digital broadcast is copied to another device, the original recorded content is encrypted and cannot be reproduced, and when the content copied to the copy destination device is deleted, The encrypted content is decrypted so that the content can be played back on the original recording device. At that time, the unique ID of the copy destination device, the ID generated from the copied content, etc. can be used as the key for decryption. Also, when copying, the content format can be converted in accordance with the copy destination device.

  According to the present invention, there is an advantage that content can be copied to another device while protecting the spirit of copy once, which is DRM for digital broadcasting. In addition, since the mobile device does not have a large-capacity recording device, it is necessary to move the high-quality content transmitted and recorded from the digital broadcast with a reduced quality. Therefore, once it was moved due to the copy-once limitation, it was not possible to restore the high-quality content. However, the present invention can restore the original content, so that the original high-quality content can be restored later. There is an advantage that you can enjoy.

  In addition, the use of bridge media for recording content for mobile devices eliminates the need to move content to mobile devices. When playing back on a recording device, the original content is encrypted, There is also an effect that it is not necessary to have both contents for use.

  Hereinafter, a content management technique according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a content management technique according to the first embodiment of the present invention, and is a diagram schematically showing a flow of processing when recording broadcast content on a recording device. FIG. 2 is a diagram schematically showing a process flow when reproducing the encrypted content recorded in the recording device. FIG. 3 is a diagram illustrating a situation in which bridge media in which mobile content is recorded is inserted into a mobile device and played back. FIG. 4 is a diagram showing a situation where the encrypted content recorded in the recording device is to be reproduced, but cannot be reproduced because no bridge media is inserted.

  As shown in FIG. 1, the content management system according to the present embodiment includes broadcast content 1, a recording / playback device 5, a storage device 7 such as a hard disk device (HDD) included therein, and a portable content playback device 17. And a bridging medium 11 such as a memory card for bridging content between the recording / reproducing device 5 and the portable content reproducing device 17. Since the bridge medium 11 has a DRM (Digital Write Management) control function, once copied to the bridge medium, it cannot be copied again from there.

  Therefore, as shown in FIG. 1, the recording / reproducing apparatus 5 receives / acquires the broadcast content 1 and the content that is subject to copy-at-once restriction (1), records it in the HDD 7 (2), and is portable. The content 15 whose format has been converted for the content reproduction device 17 is recorded in the bridge medium 11 (3). At this time, an encryption key 15 is created from the content recorded on the bridge medium 11 (4), and the original content 1a recorded on the recording / reproducing apparatus 5 is encrypted using this encryption key to encrypt the encrypted content 3 (5). The original content 1a is deleted (6). If the bridge media 11 on which the format-converted content 11 is recorded is inserted into the portable content playback device 17, the content can be played back.

  As shown in FIG. 2, when reproducing the encrypted content 3 recorded in the recording / reproducing device 5, the decryption key is used from the content 15 for the portable content reproducing device 17 recorded in the bridge medium 11. (1), the encrypted content 3 is decrypted using the key (2), and the decrypted content 1b is reproduced.

  As shown in FIG. 3, when the bridge media 11 is inserted into the portable content playback device 17, the content can be played back by the portable content playback device 17 (1). The copy of the content 15 for the portable content reproduction device 17 recorded on the bridge medium 11 is prohibited by the DRM function of the bridge medium 11 itself. The bridge medium 11 can be a flash memory or a recordable disk. As an encryption system for encryption / decryption, a known technique such as a common key cryptosystem or a public key cryptosystem can be used. Also, the hash value of the content whose format has been converted can be used as a key for encryption / decryption.

  As shown in FIG. 4, when the encrypted content 3 recorded in the recording / reproducing device 5 is to be reproduced, the decryption key 15a cannot be created because the bridge media 11 is not inserted, and the encrypted content 3 is It cannot be decrypted and played back.

  Next, the processing flow will be described with reference to the drawings. FIG. 13 is a flowchart showing a process flow when the recorded content is encrypted and written to the bridge medium 11. FIG. 14 is a flowchart showing a processing flow when decrypting and reproducing the encrypted and recorded content. First, the process is started (step S1: START), and in step 2, it is determined whether or not the bridge medium can be used in the system. In the case of No, the process proceeds to step S11, the flag is set to “0”, and the process proceeds to step S5 described later. In the case of Yes, it progresses to step S3 and it is judged whether DRM of the bridge media 11 can be used. In the case of No, the process proceeds to step S11, the flag is set to “0”, and the process proceeds to step S5 described later. In the case of Yes, it progresses to step S4 and sets a flag to "1". Step Next, in step S5, the broadcast data is received, and in step S6, the broadcast data is recorded on the recording device.

  In step S7, it is determined whether or not the flag is “1”. If it is “1” (Yes), the content format conversion is performed for the portable content playback device 17 in step S12, and the bridge media in step S13. 11 stores the data for the portable content reproduction device 17 and proceeds to step S8. If the flag is “0”, the process proceeds to step S8. In step S8, it is determined whether or not the recording is finished. If not finished (N), the process returns to step S5. If it is Y, it will progress to step S9 and it will be determined whether a flag is "1". If the flag is “0”, the process is terminated (END), and if the flag is “1” (Y), the process proceeds to step S14, the content recorded on the bridge medium is made uncopyable, and portable in step S15. An encryption key is generated from the content playback device 17 content, the content recorded in the recording device in step S16 is encrypted, the original content recorded in the recording / playback device 5 is deleted in step S17, and the process is terminated ( END).

  As shown in FIG. 14, processing is started in step S21 (START), and it is determined in step S22 whether or not the content is encrypted. If the content is not encrypted (N), the process proceeds to step S31, and it is determined whether or not all data of the content has been extracted in step S31. If all the data has been extracted (Y), the process ends in step S30 (END). In the case of N, the recorded content data is taken out, the data taken out in step S33 is reproduced, and the process returns to step S31.

In the case of Y in step S22, the process proceeds to step S23, and it is determined whether or not the bridge medium is usable. If it cannot be used (N), the process proceeds to step S30. If available (Y), the process proceeds to step S24, and it is determined whether mobile content is recorded on the bridge medium. If it cannot be used (N), the process proceeds to step S30. If available (Y), the process proceeds to step S25, and a decryption key is generated from the content recorded on the bridge medium. Next, the process proceeds to step S26, where it is determined whether or not all data of the encrypted content has been extracted. In the case of Y, the process proceeds to step S30. In the case of N, the process proceeds to step S27, and the encrypted content data recorded on the recording medium is taken out. In step S28, the content recorded on the recording medium is decrypted. The data decoded in step S29 can be reproduced. The process ends in step S30.

  Next, a content management technique according to the second embodiment of the present invention will be described with reference to the drawings.

  FIG. 5 is a diagram showing a configuration example of a content management system according to the second embodiment of the present invention. In the present embodiment, the portable content playback device 17 includes the broadcast content 1, the recording / playback device 5, the storage device 7 such as a hard disk device (HDD) included therein, and the recording device 23 such as a built-in HDD device. And a connection cable L that connects the recording / playback apparatus 5 and the portable content playback device 17 to enable data exchange.

  In the above system, the content 1 subject to copy-once restriction is received from the digital broadcast (1) and recorded in the recording / playback device 5 (2). Next, the content 1 recorded in the recording / reproducing device 5 is copied to the portable content reproducing device 17 via, for example, the wired cable L (3). At this time, the content 1a recorded in the recording / playback device 5 is encrypted (5), and the key 23 for decrypting the encrypted content 3 or the information 23 for generating the key is the portable content playback device 17 side. Saved in. The means for connecting the recording / playback device 5 and the portable content playback device 17 may be wired such as USB or iLINK, or may be wireless such as a wireless LAN or Bluetooth. When copying content to the portable content playback device 17, it is also possible to convert it to a format suitable for the portable content playback device 17 and copy it (3). For example, MPEG2 format is H.264. An example of conversion to H.264 format is given. Next, an encryption key is created based on the format-converted content 23 (4). Using the encryption key, the content 1a is encrypted to create the encrypted content 3 (5). At this time, the content 1a is deleted (6).

  As a key for encryption / decryption, a hash key value of content whose format has been converted can be used. As a cryptographic system for encryption / decryption, a known common key cryptosystem or public key cryptosystem can be used. When decrypting the encrypted content, the decryption key is extracted from the mobile device and decrypted.

  Note that the recording of the content in the recording / playback device 5 and the copy of the content in the portable content playback device 17 may be continuous in time or may be separated in time.

  FIG. 6 is a diagram showing a situation in which the mobile content 23 recorded in the portable content playback device 17 is played back. As shown in FIG. 6, since the mobile content 23 has been converted into a format that can be played back by format conversion, it can be played back without any particular problem. FIG. 7 is a diagram showing a situation where the encrypted content 3 stored in the storage device 7 of the recording / playback device 5 cannot be played because it is encrypted, and there is no decryption key in the storage device 7. Cannot decrypt.

  FIG. 8 is a diagram showing a state of processing when a decryption key is generated from the content recorded in the portable content playback device 17 and the encrypted content 3 recorded in the recording / playback device 5 is decrypted. As shown in FIG. 8, when a decryption key is generated from the storage device 21 of the portable content reproduction device 17 based on the information 23 (1). The format-converted content 23 is deleted (2). The encrypted content 3 is decrypted with the decryption key sent to the recording / reproducing device 5 (3), the encrypted content 3 is deleted (4), and the content 1b is generated (5). As a result, the content can be reproduced in the recording / reproducing apparatus 5. On the other hand, the portable content playback device 17 cannot play back the content because the format-converted content 23 has been deleted.

FIG. 15 is a flowchart showing a flow of processing for encrypting the recorded content and copying the mobile content to the portable content playback device 17. First, when the process is started (step S41: START), it is determined whether or not the portable content playback device 17 is connected to the recording / playback device 5 in step S42. In the case of N, the process proceeds to step S49 and the process is terminated (END). If it is Y, it will progress to step S43 and it will be judged whether the content is not encrypted. If the content is encrypted (N), the process proceeds to step S49, and the process ends. If the content is encrypted (Y), the process proceeds to step S44. In step S44, the content is converted into a mobile format, and mobile content is generated. Next, in step S45, the content for the portable content reproduction device 17 is transmitted.

  At this point, the portable content player 17 starts processing (step S50: START), and receives mobile content in step S51. In step S52, this content is recorded, and in step S53, an encryption key is created from this content. Next, in step S54, the encryption key is transmitted to the recording / reproducing device 5, and the process is terminated (step S55: END).

  The recording / reproducing device 5 that received the encryption key in step S46 encrypts the content in step S47, deletes the original content in step S48, and ends the process in step S49.

  FIG. 16 is a flowchart showing the flow of processing when content is deleted from the portable content playback device 17 and the content recorded after being encrypted in the recording / playback device 5 is decrypted. First. In step S61, processing of the recording / reproducing device 5 is started (START), and in step S62, it is determined whether or not the portable content reproducing device 17 is connected. If not connected (N), the process proceeds to step S68 and the process is terminated (END). If it is Y, it will progress to step S63 and it will be determined whether the content is encrypted. In step S 64, a request for a decryption key is transmitted to the portable content reproduction device 17. The portable content playback device 17 starts processing (step S69: START), and receives a decryption key from the recording / playback device 5 in step S70. In step S71, a decryption key is generated from the mobile content, and the generated key is sent to the recording / reproducing apparatus 5. In step S73, the mobile content is deleted, and the process ends in step S74.

  The recording / reproducing device 5 that has received the decryption key in step S65 decrypts the encrypted content in step S66. The content encrypted in step S67 is deleted, and the process proceeds to step S68.

  As described above, it is possible to reversibly and continuously perform the process of playing back the content on either the recording / playback device 5 or the portable content playback device 17.

  Next, a content management technique according to the third embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a diagram illustrating a configuration example of a system according to the present embodiment. As shown in FIG. 9, in the system according to the present embodiment, content 1 is received (1) content 1 is recorded in recording device 7 of recording / reproducing device 5, and then content 23 for portable content reproducing device 17 is used. Is generated by format conversion and sent (the recording device 7 of the storage / playback device 5 retains the encrypted content 3 encrypted using the unique code of the portable content playback device 17 and the content 1a is deleted). (6)), content (information) 23 is stored in the storage device 21. As a result, the content can be played back on the portable content playback device 17.

  On the other hand, as shown in FIG. 10, when content is played back on the recording / playback apparatus 5 based on the encrypted content 3, the decryption key generated using the unique code of the portable content playback device 17 is recorded and played back. When sent to the device 5 (1), the content 23 for the portable content playback device 17 is deleted (2). The encrypted content 3 is decrypted with the decryption key (3), and the encrypted content 3 is deleted (4). In the recording / reproducing apparatus 6, the content can be reproduced based on the decrypted content 1b.

  As an encryption system for encryption / decryption, a known common key encryption method or public key encryption method can be used. As a key for encryption / decryption, a unique number (manufacturing number or the like) of the portable content reproduction device 17 or a part used in the portable content reproduction device 17 can be used.

  FIG. 17 is a flowchart showing the flow of processing when the recorded content is encrypted and the mobile content is copied to the portable content playback device 17. As shown in FIG. 17, first, processing is started in the recording / reproducing apparatus 5 (step S81: START), and it is determined whether or not the portable content reproducing apparatus 17 is connected in step S81. If not connected (N), the process proceeds to step S89. If it is connected (Y), the process proceeds to step S83, if it is encrypted (N), the process proceeds to step S89, and if not encrypted (Y), the process proceeds to step S84. In step S84, the format is converted for the portable content playback device 17, and the content for the portable content playback device 17 is created. In step S85, this content is transmitted to the portable content reproduction device 17. The portable content player 17 starts processing (step S90), and receives this content in step S91. In step S92, this content is recorded, and in step S93, an encryption key is generated based on the unique ID of the portable content playback device 17. In step S94, the encryption key is transmitted, and the process ends (step S95: END). The transmitted encryption key is received by the recording / reproducing apparatus 5 in step S86, and the content is encrypted in step S89. In step S88, the original content is deleted, and the process proceeds to step S89.

  FIG. 18 is a flowchart when content is deleted from the portable content playback device 17 and the content recorded after being encrypted in the recording device is decrypted. As shown in FIG. 18, processing is started on the recording / reproducing apparatus 5 side (START: step 101), and it is determined whether or not the portable content reproducing device 17 is connected in step S102. If the portable content player 17 is not connected in step S103 (N), the process proceeds to step S108 and the process is terminated (END). In the case of Y, the process proceeds to step S103, and it is determined whether or not the content is encrypted. If not encrypted (N), the process proceeds to step S108. If encrypted (Y), in step S104, the portable content playback device 17 is requested to transmit a decryption key. The portable content player 17 has started processing (step S109), receives a request for a decryption key in step S110, and generates a decryption key based on the unique ID of the portable content player 17 in step S111. . The decryption key generated in step S102 is transmitted to the storage / reproduction device 5, and the process ends (step S114).

  The storage / reproduction device 5 receives the decryption key in step S105, and decrypts the encrypted content in step S106. In step S107, the encrypted content is deleted and the process is terminated.

  Next, a content management technique according to the fourth embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a diagram illustrating a configuration example of a content management system according to the present embodiment. As shown in FIG. 11, after the broadcast content 1 is acquired / recorded by the recording / playback device 5 (1, 2), an encryption / decryption key is generated (3), and the mobile is performed by processing including format conversion. Content is generated and stored in the portable content playback device 17 (4). When the decryption key is also copied to the portable content player 17 (5), the encrypted content 3 is created based on the content 1a and the encryption key (6). Further, the contents 1a and the encryption / decryption key are deleted (7), (8). In this state, the portable content reproduction device 17 can reproduce the content by the content 3 whose format has been converted. On the other hand, the recording / reproducing apparatus 5 cannot reproduce the content because there is no decryption key.

  FIG. 12 is a diagram showing a process of decrypting the encrypted content 3 recorded in the recording / reproducing device 5 using the decryption key recorded in the portable content reproducing device 17, and is a diagram following FIG. is there. As shown in FIG. 12, when the decryption key stored in the storage device 21 of the portable content playback device 17 is passed to the recording / playback device 5 (1), the content 3 and the decryption key are deleted (2, 5). On the recording / reproducing apparatus 5 side, the encrypted content 3 is decrypted based on the decryption key (3), and the encrypted content 3 is deleted (4). The content can be reproduced in the recording / reproducing device 5 by the decrypted content 1b.

  As an encryption system for encryption / decryption, a known common key encryption method or public key encryption method can be used. A random number generated by the recording / reproducing apparatus 5 can be used as a key for encryption / decryption.

  FIG. 19 is a flowchart showing a flow of processing for encrypting the recorded content and copying the mobile content to the portable content playback device 17. As shown in FIG. 19, first, in the recording / reproducing apparatus, processing is started (step S121: START), and in step S122, it is determined whether or not the portable content reproducing device 17 is connected. If not connected (N), the process proceeds to step S131 to end the process (END). In the case of Y, the process proceeds to step S123, and it is confirmed whether the content is not encrypted. If the content is encrypted (N), the process proceeds to step S131. If it is not encrypted (Y), the process proceeds to step S124, and an encryption / decryption key is generated. In step S125, the content is converted into a format for the portable content playback device 17, and content for the portable content playback device 17 is generated. In step S126, the generated mobile content is transmitted to the portable content playback device 17. The portable content player 17 starts processing (step S132), receives mobile content in step S133, and stores the content in step S134. In step S127, the recording / playback apparatus transmits a decryption key. In step S144, the portable content playback device 17 receives the decryption key. In step S145, the decryption key is recorded. In step S146, the process ends.

  In step S128, the content is encrypted, in step S129, the original content is deleted, in step S130, the encryption / decryption key is deleted, and the process ends (step S131).

  FIG. 20 is a flowchart showing a processing flow when decrypting content recorded by deleting the content from the portable content playback device 17 and encrypting it in the recording / playback device. As shown in FIG. 20, first, in the recording / playback device, the process starts in step S151 (START), and in step S152, it is determined whether the portable content playback device 17 is connected. If not connected (N), the process proceeds to step S158 and the process is terminated (END). In the case of Y, it progresses to step S153 and it is determined whether the content is encrypted. If the content is not encrypted (N), the process proceeds to step S158. If it is encrypted (Y), a decryption key request is transmitted to the portable content playback device 17 in step S154. The portable content player 17 starts processing (step S159), receives a request for a decryption key in step S160, and transmits the decryption key to the recording / playback device 5 in step S160. When the decryption key is received in step S155, the content is decrypted in step S156. The content encrypted in step S157 is deleted, and the process proceeds to step S158 (END).

  As described above, according to the content management technology according to the embodiment of the present invention, there is an advantage that the content can be copied to other devices while protecting the spirit of copy once, which is DRM of digital broadcasting. is there. In addition, since the mobile device does not have a large-capacity recording device, it is necessary to move the high-quality content transmitted and recorded from the digital broadcast with a reduced quality. Therefore, once it was moved due to the copy-once limitation, it was not possible to restore the high-quality content. However, the present invention can restore the original content, so that the original high-quality content can be restored later. There is an advantage that you can enjoy.

  In addition, the use of bridge media for recording content for mobile devices eliminates the need to move content to mobile devices. When playing back on a recording device, the original content is encrypted, There is also an effect that it is not necessary to have both contents for use.

  The present invention can be used as a content management system.

It is a figure which shows the outline | summary of the content management technique by the 1st Embodiment of this invention, and is the figure which showed schematically the flow of the process at the time of recording the broadcast content on a recording device. It is the figure which showed roughly the flow of the process at the time of reproducing | regenerating the encrypted content currently recorded on the recording device. It is the figure which showed the condition which inserts and reproduces | regenerates the bridge | bridging medium with which the content for mobiles was recorded in a mobile apparatus. It is the figure which showed the condition which tries to reproduce | regenerate the encrypted content currently recorded on the recording device, but cannot reproduce | regenerate because the bridge media is not inserted. It is a figure which shows the example of 1 structure of the content management system by the 2nd Embodiment of this invention. It is the figure which showed the condition of reproducing | regenerating the mobile content recorded on the portable content reproduction | regeneration apparatus. It is the figure which showed the condition which cannot reproduce | regenerate, since the encrypted content stored in the memory | storage device of a recording / reproducing apparatus is encrypted. It is a figure which shows the mode of a process at the time of producing | generating a decoding key from the content currently recorded on the portable content reproduction | regeneration apparatus, and decoding the encryption content recorded on the recording / reproduction | regeneration apparatus. It is a figure which shows the structural example of the content management system by the 3rd Embodiment of this invention. It is a figure which shows a mode that a content is reproduced | regenerated in a recording / reproducing apparatus based on encrypted content. It is a figure which shows the example of 1 structure of the content management system by the 4th Embodiment of this invention. FIG. 12 is a diagram illustrating processing for decrypting encrypted content recorded in the recording / playback device using a decryption key recorded in the portable content playback device, and is a diagram subsequent to FIG. 11. It is a flowchart figure which shows the flow of a process at the time of encrypting the recorded content and writing in a portable content reproduction apparatus to bridge | bridging media. It is a flowchart figure which shows the flow of a process at the time of decoding and reproducing | regenerating the content recorded by encryption. It is a flowchart figure which shows the flow of a process at the time of decoding and reproducing | regenerating the content recorded by encryption. It is a flowchart figure which shows the flow of a process at the time of deleting the content deleted from the portable content reproduction | regeneration apparatus and encrypting and recording the content recorded on the recording / reproduction apparatus. It is a flowchart figure which shows the flow of a process at the time of encrypting the recorded content and copying a mobile content to a portable content reproduction apparatus. FIG. 10 is a flowchart when content is deleted from a portable content playback device and decrypted by encrypting and recording in a recording device. It is a flowchart figure which shows the flow of a process which encrypts the recorded content and copies a mobile content to a portable content reproduction apparatus. It is a flowchart figure which shows the flow of a process at the time of deleting the content deleted from the portable content reproduction | regeneration apparatus and encrypting and recording the content recorded on the recording / reproduction apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Broadcast content, 5 ... Recording / reproducing apparatus, 7 ... Memory | storage device, 11 ... Bridge media, 17 ... Portable content reproduction | regeneration apparatus.

Claims (16)

A content management method for exchanging content (hereinafter referred to as content) with copy-at-once restrictions between a first device and a second device using a bridge medium,
Storing content data in the first device;
Converting the content data into a format reproducible in the second device in the first device, and copying the converted content data to a bridge medium;
Generating an encryption key based on the converted content data;
Encrypting content data stored in the first device with the generated encryption key to generate encrypted content data, and deleting the original content data. . Generating a decryption key based on the converted content data;
The content management method according to claim 1, further comprising: decrypting the encrypted content data with the decryption key. A content management method for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
Storing content data in the first device;
Converting the content data into a format reproducible in the second device in the first device, and copying the converted content data to the storage unit of the second device;
Generating an encryption key based on the converted content data;
Encrypting content data stored in the first device with the generated encryption key to generate encrypted content data, and deleting the original content data. . Generating a decryption key based on the converted content data, and deleting the converted content data;
4. The content management method according to claim 3, further comprising the step of decrypting the encrypted content data with the decryption key and deleting the original encrypted content data. A content management method for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
Storing content data in the first device;
Converting the content data into a format reproducible in the second device in the first device, and copying the converted content data to the storage unit of the second device;
Generating an encryption key based on data unique to the second device;
Encrypting content data stored in the first device with the generated encryption key to generate encrypted content data, and deleting the original content data. . Generating a decryption key based on the unique data and deleting the converted content data;
6. The content management method according to claim 5, further comprising the step of decrypting the encrypted content data with the decryption key and deleting the original encrypted content data. A content management method for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
Storing content data in the first device;
Converting the content data into a format reproducible in the second device in the first device, and copying the converted content data to the storage unit of the second device;
Generating an encryption key / decryption key in the first device;
The content data stored in the first device is encrypted with the generated encryption key to generate encrypted content data, the original content data is deleted, and the decryption key is transferred to the second device. A content management method comprising: moving and deleting the encryption key. Moving the decryption key to the first device;
The content management method according to claim 7, further comprising the step of decrypting the encrypted content data with the decryption key and deleting the original encrypted content data. A content management system for exchanging content (hereinafter referred to as “content”) to which a copy-at-once restriction is applied by a bridge medium between a first device and a second device,
Provided in the first device;
A first storage unit for storing content data;
A conversion unit that converts the content data into a format that can be reproduced by the second device;
A copy processing unit for copying the converted content data to the bridge medium;
An encryption key creating unit for generating an encryption key based on the converted content data;
And a first processing unit that encrypts content data stored in the first device with the generated encryption key to generate encrypted content data, and deletes the original content data. Content management system. A decryption key creation unit for generating a decryption key based on the converted content data;
The content management method according to claim 9, further comprising: a second processing unit that decrypts the encrypted content data with the decryption key. A content system for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
A storage unit for storing content data;
A conversion unit for converting the format of the content data into a format reproducible on the second device;
A copy processing unit for copying the converted content data to the storage unit of the second device;
An encryption key generation unit that generates an encryption key based on the converted content data;
And a first processing unit that encrypts content data stored in the first device with the generated encryption key to generate encrypted content data, and deletes the original content data. Content management system. A decryption key creation unit for generating a decryption key based on the converted content data;
12. The apparatus according to claim 11, further comprising a second processing unit that deletes the converted content data, decrypts the encrypted content data with the decryption key, and deletes the original encrypted content data. The content management system described. A content management system for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
A storage unit for storing content data;
A conversion unit for converting the format of the content data into a format reproducible on the second device;
A copy processing unit for copying the converted content data to the storage unit of the second device;
An encryption key generation unit that generates an encryption key based on data unique to the second device;
And a first processing unit that encrypts content data stored in the first device with the generated encryption key to generate encrypted content data, and deletes the original content data. Content management system. A decryption key generation unit that generates a decryption key based on the unique data, and deletes the converted content data, decrypts the encrypted content data using the decryption key, and deletes the original encrypted content data The content management system according to claim 13, further comprising: a second processing unit. A content management system for exchanging content with copy-at-once restrictions by connecting a first device and a second device,
A storage unit for storing content data;
A conversion unit for converting the format of the content data into a format reproducible on the second device;
A copy processing unit for copying the converted content data to the storage unit of the second device;
An encryption key / decryption key generation unit for generating an encryption key / decryption key;
The content data stored in the first device is encrypted with the generated encryption key to generate encrypted content data, the original content data is deleted, and the decryption key is transferred to the second device. And a first processing unit that moves and deletes the encryption key. 16. The content according to claim 15, further comprising: a second processing unit that receives the decryption key by a move, decrypts the encrypted content data using the decryption key, and deletes the original encrypted content data. Management system.

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