JP5243758B2 - Content management method, program thereof, and recording medium - Google Patents

Description

  The present invention relates to technology related to content management in a computer that manages the use of content that requires copyright protection such as digital broadcasting.

  Since the content provided by digital broadcasting is digital data, the quality does not deteriorate no matter how many times it is copied. Therefore, in Japan, restrictions are placed on copying in order to protect copyrights such as digital broadcasting.

  In Japan, a copy control signal of “copy once (can be recorded only once)” has been added to all programs in digital broadcasting since April 5, 2004. When a program is recorded by a terrestrial digital broadcast compatible HDD (Hard Disc) recorder or a personal computer (computer), the recording itself is counted as one copy. Therefore, when a copy of a program cannot be made and copied to a DVD (Digital Versatile Disc) for storage, it is performed only by a function called “move (or move out)” and recorded in the HDD (hard disk). Data is erased. At this time, the usable DVD device must be compatible with CPRM (Content Protection for Recordable Media).

On the other hand, the current copy-once is not easy to use because the original data in the HDD is erased at the same time that the data once recorded on the HDD recorder is moved to a DVD or the like. In addition, there has been a problem that no data remains in both the HDD and DVD when the DVD is bad.
Therefore, a proposal to relax the mechanism of "copy once" and allow multiple copies is being studied by the review committee of the Ministry of Internal Affairs and Communications. For example, even if a digital broadcast is recorded on an HDD recorder and then copied to a recording medium such as a DVD, a portable player, or a game machine, the recorded data in the original HDD is not erased if the copy is made multiple times. However, re-copying from copied media is not possible, as it is now.

  Japanese Patent Application Laid-Open No. 2004-151820 discloses a technique for managing the number of copies and the number of copy restrictions for each content based on the content management information so that copying cannot be performed exceeding the number of copy restrictions. Furthermore, in order to prevent the content management information from being duplicated and used, it is disclosed that information for identifying that the content management information is the latest is managed by a hash value. The functions such as content management and content decryption processing are stored in a tamper-resistant module, and the content management information created by the content management processing is stored in a nonvolatile memory, thereby improving security. I am trying.

In Patent Document 1, when the size of the content management information increases and exceeds the storage capacity of the non-volatile memory that is a secure area, the content management information is encrypted and recorded in a general-purpose storage device. Each time the content management information is updated, information (hash value) indicating that the content management information is the latest is recorded and managed in the nonvolatile memory.
JP 2007-150970 A (see paragraph 0050)

  However, in the method described in Patent Document 1, the content management information recorded in the general-purpose storage device is easily copied by the backup software, and the copied content management information indicates that it is the latest. A hash value can be created. That is, there is a possibility that the number of copies can be returned to the previous state. Therefore, an object of the present invention is to make it possible to add a secure storage area.

In order to solve the above-mentioned problem, the present invention stores a first storage medium for storing the content and content management information for managing the use of the content for the use of the content requiring copyright protection. A content management method in a computer managed using a second storage medium and a third storage medium having a secure storage area, each time the computer uses content stored in the first storage medium Updating means for updating the content management information, free size comparison means for comparing the free size of the storage area of the second storage medium with the size of the content management information to be newly stored, and the second storage Storage capacity comparison means for comparing the storage capacity of the medium and the storage capacity of the third storage medium, when the third storage medium is added A control device having link information read / write means for writing link information relating to the third storage medium to the content management information stored in the second storage medium or reading the link information; The update unit updates the content management information, the free size comparison unit compares the size of the content management information with the free size of the storage area of the second storage medium, and If the size of the content management information to be stored in the storage area of the second storage medium is less than or equal to the free size of the storage area, the update means stores the content management information in the second storage medium, When the size of the content management information to be newly stored is larger than the free size of the storage area of the second storage medium, Serial reads the link information of the link information writing means and the third storage medium, the storage capacity comparing means compares the storage capacity of the storage capacity and the third storage medium of the second storage medium, said first If the storage capacity of the third storage medium is less than the storage capacity of the second storage medium stores a portion of the content management information storage area of the update unit is the third storage medium, before Symbol first When it is determined that the storage capacity of the third storage medium is larger than the storage capacity of the second storage medium , the update unit stores all of the content management information in the storage area of the third storage medium It is characterized by this.

  Content management information important for content management is stored in a secure storage area, protected so as not to be easily altered, and a secure storage area can be expanded.

Embodiment
A content management system that manages the use of content that requires copyright protection will be described with reference to FIG. FIG. 1 is a diagram illustrating a content management system that manages the use of content that requires copyright protection.
The content management system 1 includes a tuner 10, a display device 30, a recording device 50, and a management device 60.
In addition, the management device 60 includes a decoding unit 20, a signal conversion unit 40, a processing unit 100 (control device), an encryption unit 130, a decryption unit 140, a storage device A200 (first storage medium), and a storage device B210 (first storage medium). 2 storage media) and an additional storage device C (third storage media) 220.
The processing unit 100 includes a content management unit 110 and a command control unit 120.

The tuner 10 has a function of selecting a specific channel from digital broadcasting and receiving a signal. It is assumed that it has a function of releasing scramble (encryption) originally applied to digital broadcasting.
The decoding unit 20 has a function of returning a signal output from the tuner 10 to a signal format that can be displayed on the display device 30.
The display device 30 is a television, a display, or the like, and has a function of displaying the output of the decoding unit 20 as a video.
When the recording device 50 is a recorder that records on a DVD, an SD memory card (registered trademark), a Blu-ray Disc (registered trademark), or the like, the signal conversion unit 40 inputs a signal suitable for each signal format. Has a function of converting the received signal.
The recording device 50 is a recorder that records on a DVD, an SD memory card (registered trademark), a Blu-ray Disc (registered trademark), and the like, and has a function of recording content on a movable storage medium.

The management device 60 has a function of managing the use of content. As described above, the management device 60 includes the decoding unit 20, the signal conversion unit 40, the processing unit 100, the encryption unit 130, the decryption unit 140, the storage device A200, the storage device B210, and the additional storage device C220. . In addition, the tuner 10, the display device 30, and the recording device 50 have a connection portion (not shown) for externally attaching. The management device 60 may be an HDD recorder or a personal computer (computer).
However, the storage device A200 is a general-purpose storage device, and there may be a plurality of storage devices. The storage devices B210 and C220 have a storage area that cannot be backed up by backup software. The storage device B210 is accessed for reading and writing first, and then the additional storage device C220 is accessed. And And there may be a plurality of storage devices having a secure storage area to be added, similar to the storage device C220.
The encryption unit 130 encrypts video data output from the tuner 10 during recording. This is because, according to the regulations of ARIB (Association of Ratio Industries and Businesses), unencrypted high-definition video data should not be sent to a general-purpose bus such as a personal computer. Note that the encrypted video data is stored in the storage device A200.
The decryption unit 140 decrypts the video data stored in the storage device A200 during playback or move-out (move).
Note that the decoding unit 20, the signal conversion unit 40, the encryption unit 130, and the decoding unit 140 described above are configured by, for example, an LSI (ASIC) for a specific application.

The processing unit 100 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory). In addition to the operating system, arithmetic programs and the like that are user programs are expanded and activated.
The processing unit 100 includes a content management unit 110 and a command control unit 120 as specific functions. The processing unit 100, the signal conversion unit 40, the recording device 50, the encryption unit 130, the decryption unit 140, the storage device A200, the storage device B210, and the storage device C220 can input and output information. Connectable via the bus.

The content management unit 110 updates the content management information every time the content stored in the storage device A200 is used, the free size of the storage area of the storage device B210, and the size of the content management information to be newly stored. Free space comparing means for comparing the storage capacity, storage capacity comparing means for comparing the storage capacity of the storage device B210 and the storage capacity of the storage device C220, and content management stored in the storage device B210 when the storage device C220 is added A link information read / write unit for writing link information related to the storage device C220 to the information or reading the link information, and an authentication unit that requires specific password information to manage the storage area in which the content management information is stored Have.
The content management information is stored in the storage device B210 while it can be recorded in the storage device B210.

  The command control unit 120 receives instructions for use of recording, reproduction, move-out (move), copy, deletion, and movement, and controls execution of a program corresponding to an operation instruction by the user. The move out (move) refers to moving the content stored in the storage device A200 to the recording device 50, and the recorded content stored in the storage device A200 is deleted. On the other hand, moving refers to changing a storage folder of content within the same personal computer.

The storage device A200 is a general-purpose storage device, and a storage area is managed by a folder path, and stores video data (content). In addition, an ID unique to the apparatus is provided.
The storage device B210 stores content management information. The storage device B210 has an area that is managed by dedicated software including authentication means that requires specific password information and cannot be backed up by backup software.
The storage device C220 also stores content management information in the same manner as the storage device B210.

Here, the relationship between the storage device B210 and the storage device C220 will be described.
When the content management information is updated, first, the content management unit 110 tries to write the updated content management information into the storage device B210. When it is determined that there is no free storage area, the content management unit 110 stores the updated content management information in the added storage device C220. Execute the writing process. In other words, in the present embodiment, the priority of writing is the order of the storage device C220 added next to the storage device B210.

The secure storage devices shown in the storage device B210 and the storage device C220 are realized by, for example, (i) a dedicated USB (Universal Serial Bus) device, (ii) another dedicated device, and (iii) an embedded device. . Examples of other dedicated devices include flash memory. Examples of embedded devices include HDDs and SSDs (Solid State Discs).
The conditions of the realization method by these devices are demonstrated below.
(I) The conditions for the implementation method using a dedicated USB device are: a) the device can be authenticated, b) the stored data is encrypted, and c) the storage area cannot be accessed by the USB mass storage class driver. D) The flash device related to the storage area cannot be removed with a soldering iron (tamper resistance), e) The flash device related to the storage area cannot be rewritten by soldering etc. (tamper resistance) ).
(Ii) The conditions of the implementation method by other dedicated devices are: a) the device can be authenticated, b) the stored data is encrypted, c) the storage area can be accessed only by the dedicated driver, d) The storage device related to the storage area cannot be removed with a soldering iron (tamper resistance). e) The storage device related to the storage area cannot be rewritten by soldering (tamper resistance). It is.
(Iii) The conditions of the implementation method by the embedded device are: a) the stored data is encrypted, and b) the storage device related to the storage area cannot be removed with a soldering iron (tamper resistance). C) The storage device related to the storage area cannot be rewritten by soldering or the like (tamper resistance).

The flow of video data (content) will be described with reference to FIG. Note that the flow of video data is indicated by broken lines.
First, the video data selected by the tuner 10 is output from the tuner 10 after the scrambling originally applied to the digital broadcast is released.
When viewing directly without recording, the video data output from the tuner 10 is transmitted to the decoding unit 20 and displayed on the display device 30.
When recording, the video data output from the tuner 10 is encrypted by the encryption unit 130 and recorded in the storage device A200 via the bus.
When reproducing the recorded video data (content), the video data is read from the storage device A 200, decrypted by the decryption unit 140, and displayed on the display device 30 via the decoding unit 20. .
In the case of move-out, video data is read from the storage device A200 and recorded on a medium such as a DVD set in the recording device 50 via the decoding unit 140, the decoding unit 20, and the signal conversion unit 40. .

  Next, information stored in the storage device A200 and the storage device B210 and the relationship between the information will be described with reference to FIGS. FIG. 2 is a diagram illustrating a relationship between information recorded in the storage device A and information recorded in the storage device B. FIG. 3 is a diagram showing details of the content management information recorded in the storage device B. Note that the storage device C220 stores content management information in the same manner as the storage device B210, and thus the description thereof is omitted.

  As shown in FIG. 2, video data (content) is recorded in the storage device A200. On the other hand, content management information is recorded in the storage device B210. The content management information includes common information and information for each content.

Next, details of the content management information recorded in the storage device B210 will be described with reference to FIG. 3 (see FIG. 1 as appropriate).
As common information shown in FIG. 3A, an ID unique to a recording device (management device 60), an ID of a CPU (processing unit 100), an ID of a motherboard (main substrate), and an ID of a secure storage device (storage device B210) , Secure storage device link information, recording device registration time, total number of contents, and others (deletion, move-in information).
Among these pieces of common information, the link information of the secure storage device is a record of the storage device or folder path to which the content management information is read and written as link information when the secure storage device is added. It is. The recording device registration time is, for example, the time when power is first turned on after purchase, the time when a clock is set, or the like.

As information for each content shown in FIG. 3B, checksum (for move), simple checksum (for reproduction), folder path, storage device ID, move flag, move status, copy count, copy limit count, copy status , And others.
The checksum (for move) is a value generated by applying content to a predetermined formula for each content. And it is used for tampering check at the time of move out.
The simple checksum (for reproduction) is a value generated by extracting data at a plurality of specific locations from data of a single content. Therefore, since the simple checksum is generated in a shorter time than the checksum, the waiting time until the video is displayed after being played back can be shortened.
The folder path and the storage device ID are information for identifying the storage device and the folder path for recording the content.
The move flag is information for indicating that the move has been completed.
The move status is information for managing the execution of the move out by setting the flag of the move status during the execution of the move out, and lowering the flag when the move out is not executed. is there.
The copy count and copy limit count are information indicating the executed copy count and the set maximum copy count, respectively. Whenever copying is executed, these pieces of information are referred to, and if the number of copies exceeds the copy limit number, the copy function cannot be executed.
The copy status is information for managing the execution of copying by setting a flag of the copy status during execution of copying and lowering the flag when copying is not executed.
Others are preliminary information.

Here, the usefulness of the checksum (when moving out) will be described (see FIG. 3 as appropriate).
At the time of move-out, confirmation by checksum is executed.
If the checksum is not used, the information associated with the content is only the folder path and the storage device ID. In other words, by restoring the content that was backed up by the backup software after the moveout, the folder path and the storage device ID match, so that the restore and moveout can be executed over and over again. turn into.
On the other hand, since the content can be identified by including the checksum in the content management information, it is possible to manage whether or not the moveout can be executed.

  Next, the flow of processing when executing recording, playback, move-out (move), copy, delete, and move will be described below.

(Recording)
The flow of processing when recording is selected in the command control unit 120 will be described with reference to FIG. FIG. 4 is a diagram showing the flow of processing when recording is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device B210 (step S301). Then, the content management unit 110 uses information such as an ID unique to a recording device, an ID of a CPU, an ID of a motherboard (main board), an ID of a secure storage device (here, storage device B210), and the like for content management. A key is created, and the created content management key is transmitted to the encryption unit 130 (step S302). The encryption unit 130 acquires content from the tuner 10 (step S303), encrypts the acquired content with the content management key, and transmits the content to the content management unit 110 and the storage device A200 (step S304). In step S304, the encryption unit 130 provides the content management unit 110 with information related to the folder path for the content storage location.
Next, the storage device A200 records the content transmitted from the encryption unit 130 (step S305). In addition, the content management unit 110 creates a checksum while receiving content (step S306).
Then, when the recording in the storage device A200 is completed, the content management unit 110 updates the content management information (step S307) and records it in the storage device B210 (step S308).

  In FIG. 4, in step S304, the encrypted content is transmitted to both the content management unit 110 and the storage device A200. However, the present invention is not limited to this, and what is recorded in the storage device A200 is The content management unit 110 may read and create a checksum. Alternatively, on the contrary, it may be recorded in the storage device A200 via the content management unit 110. In any case, in this embodiment, recording in the storage device A200 and creation of a checksum are performed in parallel.

Here, the effect obtained by configuring the processing flow during recording as described above will be described below.
For example, by creating a checksum for each content in step S306, it is possible to easily confirm the validity of the content when performing a move-out. Then, by recording the content management information including the checksum in the secure storage area in step S308, it is possible to reliably prevent unauthorized use of the content after recording.

(Regeneration)
The flow of processing when playback is selected in the command control unit 120 will be described with reference to FIG. FIG. 5 is a diagram showing the flow of processing when playback is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device B210 (step S321). Next, a reproduction list is created based on the content management information (step S322) and displayed on the display device 30 (step S323). Note that when creating a play list in step S323, if the move status or move flag is set (move out is being executed or has been executed), or if no content is found, it is not included in the play list. Shall.

  Then, the content management unit 110 accepts the content name for reproduction selected based on the reproduction list displayed on the display device 30 (step S324). Next, the content management unit 110 reads a simple checksum (simple checksum A) recorded in advance in the content management information acquired in step S321 (step S325). On the other hand, the content management unit 110 acquires content (video data) corresponding to the received content name from the storage device A200, and creates a simple checksum (simple checksum B) (step S326). Then, the content management unit 110 compares the simple checksum (simple checksum A) read in step S325 with the simple checksum newly created in step S326 (simple checksum B), and whether or not they match. Is determined (step S327).

  If the simple checksums A and B do not match (No in step S327), the reproduction is not performed and the process ends. On the other hand, if the simple checksums A and B match (Yes in step S327), the content management key for releasing the encryption is transmitted to the decryption unit 140 (step S328).

  Then, the decryption unit 140 acquires the content from the storage device A200 and executes decryption (step S329). Further, the decoding unit 20 converts the decoded signal into a display signal (step S330), and the display device 30 displays the video (step S331). When content is acquired from the storage device A200, the location of the content is acquired from the folder path of the content management information.

Here, an effect obtained by configuring the flow of processing during reproduction as described above will be described below.
For example, in step S327, the simple checksum B newly created from the content stored in the storage device A200 is compared with the simple checksum A recorded in the content management information, so that the reproduction can be easily performed in a short time. Can be started.

(Move out)
“Move out” refers to recording the content stored in the storage device A200 in the recording device 50.
Then, the flow of processing when move out (move) is selected in the command control unit 120 will be described with reference to FIG. FIG. 6 is a diagram showing the flow of processing when move-out is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device B210 (step S341). Then, the content management unit 110 acquires the content from the storage device A200 and creates a new checksum B (step S342). Then, the content management unit 110 compares the checksum A read from the content management information acquired in step S341 with the checksum B newly created in step S342 (step S343).

If the checksums A and B do not match (No in step S343), the move-out is not executed and the process ends.
On the other hand, if the checksums A and B match (Yes in step S343), the content management unit 110 sets a move status flag (sets from 0 to 1) and executes moveout (step S344). That is, the move status of the content management information is changed.

Next, the content management unit 110 determines whether the move is successful or not (step S345). When the move is successful (Yes in step S345), the content management unit 110 sets the move flag (sets from 0 to 1) and lowers the move status flag (sets from 1 to 0) (step S346). Then, the content management unit 110 executes a process of deleting the content (recorded data) of the move source (Step S347), and deletes the content of the move source from the storage device A200 (Step S348).
Next, the content management unit 110 updates the content management information (step S349) and records it in the storage device B210 (step S350). The content management information recorded in step S350 differs from the content management information acquired in step S341 in that a move flag is set.
On the other hand, if the move is not successful in step S345 (No in step S345), the data at the move destination is deleted and the move status is lowered (set from 1 to 0) (step S351).

  In FIG. 6, 1 is set when the flag of the move status is set, and 0 is set when the flag is lowered. Also, the move flag is set to 1 when setting the flag in FIG. 6, but is not limited to this and may be set to be identifiable.

In addition, the effect obtained by configuring the flow of processing at the time of move-out as described above will be described below.
For example, in step S343, the use of the content is reliably managed by comparing the checksum B newly created from the read content with the checksum A stored in the content management information whose validity is confirmed. It becomes possible.

(Move)
“Move” refers to moving content to a storage area of a different folder path within the same management device 60. Therefore, it is different from the move out (move) for recording on the recording medium of the recording device 50.
The flow of processing when movement is selected in the command control unit 120 will be described with reference to FIG. FIG. 7 is a diagram showing the flow of processing when movement is selected.
As a premise of the migration process, it is assumed that the storage devices are connected to the same personal computer and have different IDs.
First, the content management unit 110 acquires content management information from the storage device B210 (step S381). Then, the content management unit 110 determines whether the movement has succeeded or not (step S382). If the move is not successful (No in step S382), the data at the move destination is deleted (step S387).
On the other hand, if the migration is successful (Yes in step S382), the folder path of the content management information and the ID of the storage device are rewritten (step S383) and recorded in the storage device B210 (step S384). Next, the content management unit 110 executes a process of deleting the source content (step S385) and deletes it from the storage device A200 (step S386). Incidentally, the content management information recorded in step S384 differs from the content management information acquired in step S381 in the folder path and storage device ID of the moved content.

Moreover, the effect by having comprised the flow of the process at the time of a movement as mentioned above is demonstrated below.
For example, since the movement is performed within the same personal computer, it is not necessary to check the validity of the content because the content is not particularly viewed when the movement is executed. For this reason, it is possible to immediately start the movement process without taking time to confirm the validity. Then, only when the movement is successful, by updating the content management information, it is possible to save the content management.

(copy)
Copying means creating a copy of the content.
The flow of processing when copying is selected in the command control unit 120 will be described with reference to FIG. FIG. 8 is a diagram showing the flow of processing when copy is selected.
First, the content management unit 110 acquires content management information from the storage device B210 (step S401). Then, the content management unit 110 extracts the copy count and the copy limit count from the content management information. Next, the extracted copy count is compared with the copy limit count (step S402). If the copy count is not smaller than the copy limit count (No in step S402), the copy is not executed and the process ends. On the other hand, if the copy count is smaller than the copy limit count (Yes in step S402), the copy is executed (step S403). If the copy is successful (Yes in step S404), the number of copies is increased by 1, the content management information is updated (step S405), and the content management information is recorded in the storage device B210 (step S406). . The content management information recorded in step S406 differs in the number of copies compared to the content management information acquired in step S401.
On the other hand, if the copy is not successful in step S404 (No in step S404), the copy destination data is deleted (step S407).

The effects of configuring the processing flow during copying as described above will be described below.
For example, when copying is performed, since the content is not particularly viewed, the validity of the content is not confirmed. For this reason, it is possible to immediately start the copy process without taking time to confirm the validity. Then, only when copying is successful, the content management information can be updated to save the content management.

(Delete)
Deletion means erasing content.
A flow of processing when deletion is selected in the command control unit 120 will be described with reference to FIG. FIG. 9 is a diagram showing the flow of processing when deletion is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device B210 (step S421). Then, the content management unit 110 executes processing for deleting the designated content (step S422), and deletes the designated content from the storage device A200 (step S423).
Next, the content management unit 110 deletes the management information related to the deleted content, decreases the total number by one, updates the content management information (step S424), and records it in the storage device B210 (step S425). Incidentally, in the content management information recorded in step S425, the management information related to the deleted content is deleted and the total number of content is reduced by 1 compared to the content management information acquired in step S421. Is different.

The effect of configuring the processing flow at the time of deletion as described above will be described below.
For example, when executing deletion, the content is not particularly viewed, and therefore the validity of the content is not confirmed. Therefore, it is possible to immediately start the deletion process without taking time to confirm the validity. Then, only when the deletion is successful, by updating the content management information, it is possible to save the content management.

Here, the storage capacity necessary for content management will be described below.
Information necessary for content management stored in the storage device B210 is common information and information for each content shown in FIGS. As for the capacity, for example, the common information and the information for each content are estimated to be 1024 bytes, respectively.
Assume that one year is 365 days, and four programs are recorded per day. The product life is estimated to be 10 years.
In this case, 1024 bytes × 365 × 4 × 10 = about 15 megabytes. Therefore, a flash memory having a capacity of at least 16 megabytes is sufficient.

Finally, the flow of processing for increasing the secure storage area will be described with reference to FIG. FIG. 10 is a diagram showing a flow of processing for increasing the secure storage area.
The content management unit 110 first reads / writes content management information from / to the storage device B210 (first storage device), and then stores information to the storage device C220 (second storage device). It shall operate with priority so as to read and write.

For example, the case where the recording process is selected will be described below.
First, it is assumed that the recording process is selected and the recording process from steps S301 to S307 in FIG. 4 is executed. Then, the free size comparing means of the content management unit 110 compares the size of the newly stored content management information with the free size of the storage area of the storage device B210, and there is no free space in the storage device B210 (for example, It is assumed that the size of the content management information is larger than the size of the storage area of the storage device B210).
After that, the content management unit 110 has already acquired the content management information in the course of the recording process. Therefore, the content management unit 110 searches the content management information and extracts the content whose number of moves is 0 (step S441). If a content with 0 moves is found (Yes in step S441), the content management unit 110 determines whether or not the actual data has been deleted for the content stored in the storage device A200. Search is performed (step S451).

  If the actual data has been deleted (Yes in step S451), the content management unit 110 deletes the management information related to the content and updates the content management information (step S452). On the other hand, if the actual data has not been deleted (No in step S451), the content management unit 110 displays a message prompting the user to delete the content on the display device 30 (see FIG. 1) (step S453).

On the other hand, the case where the storage device C220 is added without the content having the number of moves of 0 being found (No in step S441) will be described below.
The link information read / write unit of the content management unit 110 writes the access destination (link information) to the added storage device C220 in the content management information stored in the storage device B210 (step S442). That is, the destination of writing is “link information of secure storage device” of the common information shown in FIG. Next, the link information of the added storage device C220 is read from the common information of the content management information (step S443), and the storage capacities of the storage device B210 and the storage device C220 are acquired (step S444). Then, the storage capacity comparison unit of the content management unit 110 compares the storage capacities of both (step S445).
If the storage capacity of the storage device C220 is larger than the storage capacity of the storage device B210 (Yes in step S445), the content management information is moved from the storage device B210 to the storage device C220 (step S446), and the storage device B210. Is initialized (step S447), and the content management information is recorded in the storage device C220 (step S448).

  When the storage capacity of the storage device C220 is less than or equal to the storage capacity of the storage device B210 (No in step S445), information that cannot be recorded because the storage device B210 is empty is recorded in the storage device C220 and content management information is shared (Step S449).

  Note that an effect of the embodiment of the present invention is that secure storage device link information can be added because the secure storage device link information is provided in the content management information. In addition, it is not necessary to prepare a storage device having a large storage capacity from the beginning, and the cost can be reduced. In addition, the storage capacity can be changed according to the usage situation.

It is a figure which shows the content management system which manages utilization of the content which requires copyright protection. 4 is a diagram illustrating a relationship between information recorded in a storage device A and information recorded in a storage device B. FIG. 4 is a diagram showing details of content management information recorded in a storage device A. FIG. It is a figure which shows the flow of a process when recording is selected. It is a figure which shows the flow of a process when reproduction | regeneration is selected. It is a figure which shows the flow of a process when a move out is selected. It is a figure which shows the flow of a process when a movement is selected. It is a figure which shows the flow of a process when a copy is selected. It is a figure which shows the flow of a process when deletion is selected. It is a figure which shows the flow of a process which increases a secure memory area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Content management system 10 Tuner 20 Decoding part 30 Display apparatus 40 Signal conversion part 50 Recording apparatus 60 Management apparatus 100 Processing part 110 Content management part 120 Command control part 130 Encryption part 140 Decoding part 200 Storage apparatus A
210 Storage device B
220 Storage device C

Claims (4)

A second storage medium having a first storage medium for storing the content and a secure storage area for storing content management information for managing the use of the content; A content management method in a computer managed using a third storage medium,
Computer
Updating means for updating the content management information every time the content stored in the first storage medium is used;
A free size comparing means for comparing the free size of the storage area of the second storage medium with the size of the content management information to be newly stored;
Storage capacity comparison means for comparing the storage capacity of the second storage medium with the storage capacity of the third storage medium;
When the third storage medium is added, a link for writing link information related to the third storage medium to the content management information stored in the second storage medium or reading the link information Information reading and writing means,
A control device having
When the content is used, the update unit updates the content management information, and the free size comparison unit compares the size of the content management information with the free size of the storage area of the second storage medium,
If the size of the content management information to be newly stored is less than or equal to the free size of the storage area of the second storage medium, the update means stores the content management information in the second storage medium,
On the other hand, when the size of the content management information to be newly stored is larger than the free space in the storage area of the second storage medium, the link information read / write means reads the link information of the third storage medium. The storage capacity comparing means compares the storage capacity of the second storage medium with the storage capacity of the third storage medium, and the storage capacity of the third storage medium is the storage capacity of the second storage medium. the storage capacity of the following stores some of the content management information storage area of the update unit is the third storage medium, if, before Symbol third storage medium of the storage capacity and the second storage medium If it is determined that the greater is that the updating means stores all of the content management information storage area of the third storage medium,
Content management method characterized by the above. A storage area in which the content management information is stored is managed by an authentication unit that requires specific password information;
The content management method according to claim 1. A second storage medium having a first storage medium for storing the content and a secure storage area for storing content management information for managing the use of the content; A content management program in a computer managed using a third storage medium,
Computer
Updating means for updating the content management information every time the content stored in the first storage medium is used;
A free size comparing means for comparing the free size of the storage area of the second storage medium with the size of the content management information to be newly stored;
Storage capacity comparison means for comparing the storage capacity of the second storage medium with the storage capacity of the third storage medium;
When the third storage medium is added, a link for writing link information related to the third storage medium to the content management information stored in the second storage medium or reading the link information Information reading and writing means,
Function as
When the content is used, the update unit updates the content management information, and the free size comparison unit compares the free size of the content management information with the size of the storage area of the second storage medium,
If the size of the content management information is less than or equal to the size of the storage area of the second storage medium, the updating means stores the content management information in the second storage medium,
On the other hand, when the size of the content management information to be newly stored is larger than the free space in the storage area of the second storage medium, the link information read / write means reads the link information of the third storage medium. The storage capacity comparing means compares the storage capacity of the second storage medium with the storage capacity of the third storage medium, and the storage capacity of the third storage medium is the storage capacity of the second storage medium. the storage capacity of the following stores some of the content management information storage area of the update unit is the third storage medium, if, before Symbol third storage medium of the storage capacity and the second storage medium If it is determined that the greater is that the updating means stores all of the content management information storage area of the third storage medium,
A content management program characterized by   A computer-readable recording medium on which the content management program according to claim 3 is recorded.

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