JP2006331134A - Reproduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reproduction device effectively practically using a data area of a memory card to move an encryption content not allowing takeout from a hard disk to another device, and allowing restoration of broken data when the hard disk causes data breakage. <P>SOLUTION: This reproduction device 100 has: the hard disk 200 recording the encryption content 211; the memory card 300 recording an encryption key 322 corresponding to the encryption content 211; and a decoder 400 decrypting the encryption content 211 by use of the encryption key 322 and outputting it. The memory card 300 is a detachable memory card, and has: a first-in first-out type buffer area 313 temporarily storing all or a part of the encryption content 211 recorded in the hard disk 200 when reproducing the encryption content; and an area 312 managing the content temporarily stored in the buffer area 313 as a file. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a playback apparatus, and more particularly to a playback buffer management method, and also relates to moving encrypted content and restoring encrypted content.

  In recent years, there have been increasing opportunities to download image and music contents by Internet distribution or ripping and enjoy them on portable devices. Many of these contents are encrypted for copyright protection in order to prevent unauthorized copying such as duplication, and memory cards with copyright protection functions are used as media for recording encrypted contents. Used. However, since the semiconductor memory has a small capacity and high cost, there is a problem that it cannot handle a large amount of encrypted content.

  Therefore, a system has been developed that has a large-capacity recording medium and a memory card having a copyright protection function, and that enables large-capacity storage of copyright-protected encrypted content (see, for example, Patent Document 1). FIG. 11 shows the configuration of a portable playback apparatus to which such a system is applied.

  A conventional portable playback device 10 shown in FIG. 11 includes a hard disk 20 for recording encrypted content 22, a memory card 30 having a copyright protection function, a buffer memory 40 for temporarily storing data during content playback, A decoder 50 for decoding and outputting contents is provided.

  The memory card 30 has a mutual authentication function between the portable playback device 10 and the host device as a copyright protection function, and the recording area of the memory card 30 is a non-secure area 31 that can be accessed without mutual authentication. The secure area 32 can be accessed only when mutual authentication is successful. The non-secure area 31 is used as the data area 33. The secure area 32 is used as an area for recording the encryption key management information 34 and the encryption key 35.

  On the other hand, the hard disk 20 includes only the non-secure area 21 and can always read and write digital data. The hard disk 20 may be another recording medium such as an optical disk or a memory card.

Next, the operation of the portable playback device 10 will be described.
In the portable playback device 10, the content is encrypted using the copyright protection function of the memory card 30 and recorded as the encrypted content 22 in the non-secure area 21 of the hard disk 20. In addition, the encryption key 35 used for encryption is recorded in the secure area 32 of the memory card 30. The secure area 32 has encryption key management information 34 for managing the encryption key 35 corresponding to the encrypted content 22 stored in the hard disk 20.

When reproducing the encrypted content 22, the data stored in the hard disk 20 is read into the buffer memory 40 via the temporary storage channel 11 and temporarily stored. The data stored in the buffer memory 40 is continuously read out to the decoder 50 via the decode channel 12, and the data decoded by the decoder 50 is output via the analog signal output channel 13.
JP 2004-94778 A

  However, while the conventional configuration includes a buffer memory for suppressing power consumption in frequent hard disk access, an unused data area remains on the memory card, which is costly and has a circuit configuration. It is disadvantaged.

  In addition, if content that is not allowed to be moved or copied due to copyright is recorded on the hard disk in the conventional configuration, when the content is recorded on the memory card, the memory card itself can be moved to While content can be moved to the device, the content cannot be removed from the recorded device.

  Further, in the conventional portable playback device, when the content recorded in the hard disk is damaged, it is difficult to repair the damaged data.

  The present invention has been made to solve the above-described problems, and effectively uses an unused data area of a memory card and moves encrypted content stored in the apparatus to another apparatus. An object of the present invention is to provide a playback apparatus capable of improving the possibility of repairing damaged data on a hard disk.

  In order to solve the above problems, a playback apparatus according to claim 1 of the present invention records a first recording medium on which encrypted content is recorded, and an encryption key corresponding to the encrypted content. And a second recording medium having a copyright protection function, and a decryption processing unit that decrypts and outputs the encrypted content using the encryption key, and recorded on the first recording medium In the playback device for playing back encrypted content, the second recording medium has a first-in first-out temporary storage area for temporarily storing all or part of the encrypted content when the encrypted content is decrypted and played back And the file management information for managing the encrypted content temporarily stored in the temporary storage area as a file, the file managed by the file management information, and the temporary And storing encryption key management information that holds an association with an encryption key corresponding to the encrypted content temporarily stored in the storage area. The decryption processing unit temporarily stores the encryption key in the temporary storage area. All or a part of the encrypted content being decrypted using the file management information and the encryption key management information, and recorded on the first recording medium by the decryption processing unit It is characterized by decrypting and reproducing the encrypted content and outputting it.

  As a result, since the encrypted content recorded on the first recording medium at the time of reproduction is temporarily stored in the second recording medium, there is no need to install a buffer memory as in the conventional case, and the system configuration is simplified. As a result, system construction can be realized at low cost. In addition, when the encrypted content stored in the first recording medium is damaged, it is possible to repair the damaged data using the encrypted content temporarily stored in the second recording medium. Become.

  The playback apparatus according to claim 2 of the present invention is the playback apparatus according to claim 1, wherein the first-in first-out temporary storage area is composed of fixed-length blocks, and the encrypted content is input in units of the blocks. The file management information is output, and the storage block position identification information for identifying the position of the block group storing the encrypted content temporarily stored in the temporary storage area and the temporary storage area are temporarily stored. The file name management information for storing the file name of the encrypted content in relation to the storage block position of the encrypted content is included.

  Thereby, it is possible to construct a file management system that makes it easy to understand how the encrypted content temporarily stored in the second recording medium is managed.

The playback device according to claim 3 of the present invention is the playback device according to claim 2, wherein the storage block position identification information is FAT in a file allocation table (FAT) file system, and the file name management information Is a directory.
As a result, a file system having an excellent management function can be constructed.

  The playback device according to claim 4 of the present invention is the playback device according to claim 1, wherein the encrypted content is decrypted in a fixed-length decryption unit, and the temporary storage area is It is composed of blocks having a data length that is a multiple of the decoding unit.

  Accordingly, it is possible to smoothly decrypt and reproduce the encrypted content decrypted in a fixed-length decryption unit.

  According to a fifth aspect of the present invention, in the reproduction apparatus according to the first aspect, the encrypted content has reproduction time management information for maintaining a relationship between a reproduction time and a reproduction position. And the second recording medium adjusts for each file temporarily stored in the temporary storage area so that the reproduction time does not deviate based on the reproduction time management information of the encrypted content corresponding to the file. It has adjustment information.

  As a result, a file composed of a part of the encrypted content temporarily stored in the second recording medium can be accurately decrypted and reproduced without any deviation in the reproduction time.

  The playback device according to claim 6 of the present invention is the playback device according to claim 1, wherein the encrypted content refers to a header reference type that refers to header information recorded at the beginning of the content at the time of playback. It is content, and the second recording medium holds header information of the encrypted content to be played back, and erases the header information of the encrypted content when the playback of the encrypted content ends. And

  Thereby, even when the file temporarily stored in the second recording medium is composed of a part of the header reference type content, it can be decoded and reproduced based on the held header information.

  According to claim 7 of the present invention, in the playback apparatus according to claim 1, the second recording medium is detachable.

  As a result, it is possible to move encrypted content that could not be extracted from the playback device in the past under the copyright law to another device, and to decrypt and play back the encrypted content without any problems in the copyright law. it can.

  According to the playback device of the present invention, when playing back the encrypted content recorded on the hard disk, the encrypted content is temporarily stored in the data area of the memory card and then decoded. In this case, the data area of the memory card that has been wasted and wasted can be used effectively. Therefore, the system configuration can be simplified without the need for a buffer memory. Therefore, it is possible to realize a reproducing apparatus having a copyright protection function at low cost. Moreover, since the encrypted content stored in the hard disk is temporarily stored in the memory card, when the encrypted content stored in the hard disk is damaged, the data temporarily stored in the memory card is used. Can be repaired. Further, since the memory card is detachable, the encrypted content can be reproduced on the other device without any problem in the copyright law only by moving the memory card to the other device.

Embodiments of a playback apparatus according to the present invention will be described below in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a playback apparatus according to Embodiment 1 of the present invention.
The playback apparatus 100 according to the first embodiment has a hard disk 200 that is a first recording medium on which the encrypted content 211 is recorded, and an encryption key 322 corresponding to the encrypted content 211 recorded thereon. A memory card 300 that is a second recording medium having a right protection function, and a decoder 400 that is a decryption processing unit that decrypts and outputs the encrypted content 211 using the encryption key 322. The recorded encrypted content 211 is reproduced.

  The hard disk 200 has a non-secure area 210, and the encrypted content 211 is recorded in the non-secure area 210.

  The memory card 300 is detachable and has a non-secure area 310 and a secure area 320. The data area 311 of the non-secure area 310 of the memory card 300 is a buffer area that is a first-in first-out temporary storage area that temporarily stores all or part of the encrypted content when the encrypted content 211 is decrypted and reproduced. 313 and an area 312 for storing file management information for managing the encrypted content temporarily stored in the buffer area 313 as a file are provided, and the secure area 320 is managed by the file management information. There is provided an area 321 for storing encryption key management information that holds the relationship between the file to be stored and the encryption key 322 corresponding to the content temporarily stored in the buffer area 313.

  In the first embodiment, the buffer area 313 is composed of a fixed-length block 313a, and the encrypted content 211 is divided and temporarily stored so as to have the same data length as the block 313a. The file management information includes storage block position identification information (file chain information 312a) for identifying a block position in which the content temporarily stored in the buffer area 313 is stored, and a file of the content temporarily stored in the buffer area 313 File name management information (file head block information 312b) that holds the name in association with the storage block position of the content is included. The storage block position identification information is a FAT in a FAT (File Allocation Table) file system, and the file name management information is a directory.

The operation of the playback apparatus 100 having such a configuration will be described with reference to FIGS. 2, 3, and 4. FIG.
When decrypting and reproducing the encrypted content 211, the encrypted content 211 stored in the hard disk 200 is read through the temporary storage channel 111, temporarily stored in the buffer area 313 of the memory card 300 in units of the block 313a, Are transferred to the decoder 400 in units of blocks 313a via the decode channel 112. At this time, the file management information is updated according to the usage status of the buffer area 313. Then, the data decoded by the decoder 400 is output via the analog signal output channel 113.

  When the hard disk 200 has data corruption, the data temporarily stored in the buffer area 313 is read via the data repair channel 114 and written to the hard disk 200 to repair the damaged data.

FIG. 2 is a diagram for explaining the temporary storage process of the encrypted content 211 in the first embodiment.
In the first embodiment, the encrypted content 211 is divided into blocks 211 a having the same data length as the blocks 313 a constituting the buffer area 313 and temporarily stored in the buffer area 313 at the time of decryption and reproduction.

  For example, as shown in FIG. 2A, the encrypted content # 1 is divided into two data blocks 211a, which are temporarily stored in the buffer area 313 as a file # 1_1 and a file # 1_2, respectively. The file # 1_1 and the file # 1_2 temporarily stored in the buffer area 313 are managed by the file management information with the file name of the file # 1.

  Also, as shown in FIG. 2B, the encrypted content # 2 is divided into three data blocks 211a, and each is temporarily stored in the buffer area 313 as file # 2_1, file # 2_2, and file # 2_3. The The file # 2_1, the file # 2_2, and the file # 2_3 temporarily stored in the buffer area 313 are managed by the file management information with the file name of the file # 2.

  Further, as shown in FIG. 2C, the encrypted content # 3 is divided into n (n is an integer of 1 or more) data blocks 211a, each of which is a file # 3_1, a file # 3_2, and a file # 3_n. Is temporarily stored in the buffer area 313. File # 3_1, file # 3_2,..., File # 3_n temporarily stored in the buffer area 313 are managed by file management information under the file name of file # 3.

  FIG. 3 is a diagram showing a file management method in the case of handling the encrypted content divided as shown in FIG. Here, it is assumed that the buffer area 313 is divided into five blocks, and the encrypted content 211 is temporarily stored in the buffer area 313 in the order of the encrypted contents # 1, # 2,.

  As shown in FIG. 3A, files # 1_1, # 1_2, # 2_1, # 2_2, and # 2_3 are temporarily stored in the blocks 1 to 5 constituting the buffer area 313, respectively. At this time, in the file head block information 312b, “1” is stored as the head block number of the file # 1, and “3” is stored as the head block number of the file # 2. Block number “2”, block number 2, and the character string “END” indicating that the corresponding block stores the last data of the data blocks constituting one file In the number 3, the next block number “4”, the block number 4, the next block number “5”, and the character string “END” are stored in the block number 5. That is, in the file management information, it is managed that the data of the file # 1 is stored in the blocks 1 and 2, and the data of the file # 1 is configured in the order of the block numbers 1 and 2, and the data of the file # 2 is managed. Are stored in blocks 3 to 5, and the data of file # 2 is managed in the order of block numbers 3, 4, and 5. This character string “END” is a system-dependent character string, and may be another character string or a numerical value.

  When the reproduction of the content is started, as shown in FIG. 3B, the file # 1_1 temporarily stored in the block 1 of the buffer area 313 is transferred to the decoder 400, and the file # 2_3 temporarily stored last time. The next data block 211a, file # 3_1, is temporarily stored in block 1 of the buffer area 313. At this time, in the file head block information 312b, the file head block number of the file # 1 is updated to “2”, the block number “1” is registered as the file head block information of the file # 3, and the file chain information 312a The character string “END” is stored in block number 1. That is, the file management information manages that the data of the file # 1 is stored only in the block 2, the data of the file # 2 is stored in the blocks 3 to 5, and the data of the file # 3 is stored only in the block 1. .

  Then, as shown in FIG. 3C, when the file # 1_2 temporarily stored in the block 2 of the buffer area 313 is transferred to the decoder 400, the next data block of the file # 3_1 temporarily stored last time File # 3_2 which is 211a is temporarily stored in block 2 of the buffer area 313. At this time, in the file head block information 312b, information related to the file head block of the file # 1 is deleted, and in the file chain information 312a, the next block number “2” is assigned to the block number 1 and “END” is assigned to the block number 2. Store. That is, the file management information manages that the data of the file # 2 is stored in the blocks 3 to 5, and the data of the file # 3 is stored in the blocks 1 and 2. Since all the information related to file # 1 has been deleted from the file management information, it can be seen that the decryption / reproduction of file # 1 has ended.

  Further, as shown in FIG. 3D, when the file # 2_1 temporarily stored in the block 3 of the buffer area 313 is transferred to the decoder 400, the next data block of the file # 3_2 temporarily stored last time is stored. File # 3_3, which is 211a, is temporarily stored in block 3 of the buffer area 313. At this time, in the file head block information 312b, the head block number of the file # 2 is updated to “4”, and in the file chain information 312a, the block number 2 is set to the next block number “3”, the block number 3 is set to “END”. "Is stored. That is, the file management information manages that the data of the file # 2 is stored in the blocks 4 to 5 and the data of the file # 3 is stored in the blocks 1 to 3.

  As described above, by updating the file management information in accordance with the usage status of the block 313a constituting the buffer area 313, the content temporarily stored in the buffer area 313 can be managed as a file.

FIG. 4 is a diagram for explaining the decryption / playback processing of the encrypted content according to the first embodiment.
When content reproduction is started (step S101), first, file management information is initially set. That is, 1 is stored in the target block number b (step S102), and the block number of the block temporarily stored last time is stored in the previous block number b_a (step S103).

  When the initial setting process is completed, the file stored in the block b is set as the decoding target file F_d (step S104), and the block b is decoded (step S105). At this time, the value of the block number b of the file chain information 312a is confirmed (step S106). If the value is “END”, the target file F_d is deleted from the file head block information 312b (step S107), and otherwise In this case, the value b_dh of the file F_d of the file head block information 312b is compared with the maximum block number N (step S108). If the value b_dh is smaller, b_dh is incremented (step S109), and the maximum block number N If equal, 1 is stored in b_dh (step S110).

  Then, the next data block 211a is temporarily stored in the block b (step S111), the file temporarily stored in the target block b is set as the target file F_t for temporary storage processing (step S112), and the previously stored block b_a is temporarily stored. The stored file and the target file F_t are compared (step S113), and if they are equal, the block number b_a of the file chain information 312a stores b which is the number of the block temporarily stored last time. (Step S114), if different, the block number b is added to the file head block information 312b as the head block number of the target file F_t (step S115). Then, “END” is stored in the block number b of the file chain information 312a (step S116), the previous block number b_a is changed to the block number b (step S117), the block number b, and the maximum block number N Are compared (step S118). If they are different, the block number b is incremented (step S119). If they are equal, the block number b is set to 1 (step S120), and the processing from step S104 is repeated.

  In the first embodiment as described above, the block 313a of the buffer area 313 is used as a temporary storage location for the encrypted content during content playback, so the data area of the memory card can be used effectively. The system configuration can be simplified without mounting a conventional buffer memory, and as a result, a reproducing apparatus can be realized at low cost. In addition, since the encrypted content subject to copyright protection stored in the hard disk 200 is temporarily stored in a memory card 300 having a copyright protection function, it is only necessary to move the memory card to another device. In other devices, encrypted content can be played back without any copyright problems, and if the hard disk is damaged, there is a high possibility that it can be repaired with the data temporarily stored on the memory card. Become.

  Also, the encrypted content 211 is divided into fixed-length data blocks 211a and temporarily stored in the buffer area 313, and the temporary storage location is managed by the file chain information 312a and the file head block information 312b. Therefore, it is possible to construct a file management system that makes it easy to understand how the encrypted content 211 is managed in the buffer area 313.

(Embodiment 2)
The playback device according to the second embodiment of the present invention handles encrypted content that is decrypted in a fixed-length decryption unit.

  The playback device of the second embodiment has the same configuration as that of the playback device of the first embodiment (shown in FIG. 1), and temporarily stores encrypted content, a file management method, and decrypts the encrypted content. The reproduction process is the same as that in the first embodiment (shown in FIGS. 2 to 4), and the description thereof is omitted here. The difference from the first embodiment is that in the first embodiment, the data length of the block constituting the buffer area 313 is determined in advance, and the encrypted content 211 is divided so as to be the same as the data length of this block. In the second embodiment, the data length of the blocks constituting the buffer area 313 is determined on the basis of the decryption unit of the encrypted content 211, and will be described below with reference to FIG. explain.

FIG. 5 is a diagram for explaining a temporary storage process of the encrypted content 211 in the buffer area 313 according to the second embodiment.
In the second embodiment, the encrypted content 211 is divided by the encryption chain 211b, which is a fixed-length decryption unit, during decryption and reproduction, and is temporarily stored in the buffer area 313. The buffer area 313 is configured by a block 313b having a data length that is a multiple (in this case, three times) of the encryption chain 211b.

  In the second embodiment, when the encrypted content 211 decrypted in the fixed-length decryption unit is decrypted and reproduced, the buffer area 313 is configured by the block 313b having a data length that is a multiple of the decryption unit. Therefore, it is possible to smoothly decrypt and reproduce the encrypted content decrypted in a fixed-length decryption unit.

(Embodiment 3)
The playback apparatus according to Embodiment 3 of the present invention handles encrypted content having playback time management information, for example, Audio content.

  The playback apparatus according to the third embodiment has substantially the same configuration as that of FIG. 1 showing the first embodiment, but the configuration of the memory card 300 is different. Therefore, the configuration of the memory card will be described with reference to FIG. . Further, the encrypted content temporary storage process and the file management method in the third embodiment are the same as the processes in the first embodiment (shown in FIGS. 2 and 3).

FIG. 6 shows a configuration of the memory card 300 of the playback apparatus according to the third embodiment.
In the third embodiment, in addition to the configuration of the first embodiment, the memory card 300 has an encrypted content corresponding to the file for each file temporarily stored in the buffer area in the non-secure area 310. An area 314 for storing time adjustment information for adjusting the reproduction time so as not to deviate based on the reproduction time management information, and an area 315 for storing the audio content management information are further provided.

  As one of the audio content management information stored in the audio content management information storage area 315, there may be a time search table 315a that holds the relationship between the playback time and the playback data position of each audio content. Note that the storage position of the audio content management information depends on the system and may be stored in the hard disk 200.

  The time adjustment information storage area 314 holds correction time information for adjusting the reproduction time managed by the time search table 315a for each file so as not to shift. For this reason, the file recorded in the buffer area 313 is composed of a part of the content, and the data of the head part is missing, so that the reproduction time held in the time search table 315a and the reproduction time of the file are reduced. When a deviation occurs, the reproduction time at each reproduction data position stored in the time search table 315a can be corrected using the correction time information held in the time adjustment information storage area 314.

  In addition, when the memory card 300 is moved to another playback device to fast forward or rewind a file, time adjustment information is stored in the playback time information at each playback data position stored in the time search table 315a. By adding the correction time of each file stored in the area 314, decryption and reproduction of the encrypted content can be performed accurately.

Next, the operation of the third embodiment will be described with reference to FIG.
FIG. 7 is a diagram for explaining the decryption / playback processing of the encrypted content according to the third embodiment.

  When content reproduction is started (step S201), first, initial setting processing, that is, processing of steps S102 to S103 in FIG. 4 is performed (step S202).

  Then, the file stored in the block b is set as the decoding target file F_d (step S203), and the block b is decoded (step S204). At this time, the value of the block number b of the file chain information 312a is confirmed (step S205). If the value is “END”, the target file F_d is deleted from the file head block information 312b (step S206), and the time The correction time information of the file F_d is deleted from the adjustment information storage area 314 (step S207). In other cases, the value b_dh of the file F_d of the file head block information 312b is compared with the maximum block number N (step S208). If b_dh is smaller, b_dh is incremented (step S209), and the maximum block number If equal to N, 1 is stored in b_dh (step S210), and the time of the data of block b is added to the correction time of the file F_d stored in the time adjustment information storage area 314 (step S211).

  Then, the next data block 211a is temporarily stored in the block b (step S212), the file temporarily stored in the block b is set as the target file F_t for the temporary storage process (step S213), and stored in the block b_a temporarily stored previously. If the file is compared with the target file F_t (step S214), if equal, the block number b_a of the file chain information 312a stores b, which is the number of the block temporarily stored last time ( In step S215), if different, the file name of the target file F_t and the block number b as the first block number are added to the file head block information 312b (step S216), and the time adjustment information storage area 314 stores the file F_t. Add correction time information and set the correction time to 0 Stores (step S217).

  Thereafter, end processing, that is, processing in steps S116 to S120 in FIG. 4 is performed (step S218), and the processing from step S203 is repeated.

  In the third embodiment, when playing back content having time management information, correction time information is managed and managed for each file temporarily stored in the buffer area 313. Since the playback time of the encrypted content is adjusted based on the information, even when playing back a file consisting of a part of the encrypted content, it can be accurately decrypted and played back so that the playback time does not deviate. .

(Embodiment 4)
The playback device according to the fourth embodiment of the present invention handles header reference type content that refers to header information at the time of playback. It is held in the buffer area 313.

  Note that the playback apparatus according to the fourth embodiment has the same configuration as that of the playback apparatus according to the first embodiment (shown in FIG. 1), and the description thereof is omitted here.

Hereinafter, the operation of the playback apparatus according to the fourth embodiment will be described with reference to FIGS. 8, 9, and 10. FIG.
FIG. 8 is a diagram for explaining temporary storage processing of encrypted content 211 in the fourth embodiment.
In the fourth embodiment, the encrypted contents # 1 to # 3 are composed of a header, data, and footer, and are divided as shown in FIGS. 8A to 8C, and decrypted and reproduced for each data block 211a. However, since the header information is included in the first block of the file, it is held in the buffer area 313 until the decoding process of the data block of the same file is completed. The header information includes, for example, content size, content stream number, content packet number, and the like.

  FIG. 9 is a diagram for explaining a file management method when handling the header reference type content divided as shown in FIG. Here, it is assumed that the buffer area 313 is divided into five blocks, and the encrypted content 211 is temporarily stored in the buffer area 313 in the order of the encrypted contents # 1, # 2,.

  As shown in FIG. 9A, files # 1_1, # 1_2, # 2_1, # 2_2, and # 2_3 of the data block 211a shown in FIG. 8 are included in the blocks 1 to 5 constituting the buffer area 313, respectively. Temporarily stored. At this time, in the file management information, the data storage positions of the file # 1 and the file # 2 are managed (similar to FIG. 3A).

  When the reproduction of the content is started, since the block 1 is the first block including the header information of the file # 1, the file # 1_1 stored in the block 1 and the block 2 as shown in FIG. # 1_2 is subsequently transferred to the decoder 400, and the file # 3_1, which is the data block 211a next to the file # 2_3 temporarily stored last time, is temporarily stored in the block 2. At this time, “2” is added as the first block number of the file # 3 in the file first block information 312b. In addition, since all data blocks other than the first block among the data blocks constituting the file # 1 are decoded, the first block information of the file # 1 is deleted. In the file chain information 312a, a character string “NIL” indicating that the corresponding block is empty is stored in block number 1. That is, the file management information manages that the data of the file # 2 is stored in the blocks 3 to 5, the data of the file # 3 is stored only in the block 2, and the block 1 is an empty block. The character string “NIL” is a system-dependent character string, and may be another character string or a numerical value.

  Next, since the block 3 of the buffer area 313 is the first block including the header information of the file # 2, the files # 2_1 and # 2_2 stored in the block 3 and the block 4 as shown in FIG. 9C. Are transferred to the decoder 400 and # 3_2 which is the next data block 211a of the file # 3_1 temporarily stored last time is temporarily stored in the block 4. At this time, the file head block information 312b is not changed. In the file chain information 312a, the value of block number 3 is updated to “5”, the next block number “4” is stored in block number 2, and “END” is stored in block number 4. That is, in the file management information, the data of the file # 2 is stored in the blocks 3 and 5, the data of the file # 3 is stored in the blocks 2 and 4, and the block 1 is managed as an empty block.

  Then, as shown in FIG. 9D, when the file # 2_3 stored in the block 5 of the buffer area 313 is transferred to the decoder 400, the data block 211a next to the file # 3_2 temporarily stored last time last time. File # 3_3 is temporarily stored in block 5 of buffer area 313. At this time, in the file head block information 312b, the head block information of the file # 2 is deleted. In the file chain information 312a, the character string “NIL” is stored in the block number 3, and “5” is stored in the block number 4. to add. That is, the file management information manages that the data of the file # 3 is stored in the blocks 2, 4, and 5 and other blocks are empty blocks.

  In the next decoding / reproducing process, since the last decoding / reproducing process (shown in FIG. 9D) uses up to block 5 which is the last block of the buffer area 313, the temporary storage of the next data block 211a Used from block 1. Therefore, as shown in FIG. 9E, the file # 3_4, which is the data block 211a next to the file # 3_3 temporarily stored last time, is temporarily stored in the block 1 which is an empty block. At this time, in the file chain information 312a, the next block number “1” is stored in the block number 5, and “END” is stored in the block number 1. Therefore, in the file management information, the data of the file # 3 is stored in the blocks 1, 2, 4, and 5, and the data of the file # 3 is configured in the order of the block numbers 2, 4, 5, and 1. I manage.

  As described above, the buffer area 313 is used in a state where the first block of the file is held, and the file management information 312 is updated according to the usage status.

FIG. 10 is a diagram for explaining the decryption / playback processing of the encrypted content according to the fourth embodiment.
When content reproduction is started (step S301), first, initial setting processing, that is, processing of steps S102 to S103 of FIG. 4 is performed (step S302).

  Then, the value of the block number b of the file chain information 312a is confirmed (step S303). If the value is “NIL”, the process from the temporary storage process S312 is performed, and otherwise, stored in the block b. The file that has been processed is set as a decoding target file F_d (step S304), and the block b is decoded (step S305).

  Then, the value of the block number b of the file chain information 312a is confirmed (step S306). If the value is “END”, “NIL” is stored in the first block of the file F_d of the file chain information 312a (step S306). In step S307, the target file F_d is deleted from the file head block information 312b (“NIL” is stored) (step S308). Otherwise, it is confirmed whether the block b is the head block of the file F_d (step S309). ). As a result of the confirmation, if the block b is the head block, the block number b is incremented (step S303) and the processing from the step (step S310) is repeated.

If block b is not the first block, temporary storage processing, that is, processing from step S111 to S115 in FIG. 4 (step S311) and termination processing, that is, processing from step S116 to S120 in FIG. 4 (step S312). And the processing from step S303 is repeated.

  In the fourth embodiment, when the encrypted content is a header reference type content, the header information of the encrypted content is held in the memory card 300 until the decryption / reproduction of the encrypted content to be reproduced is completed. Thus, even when a file composed of a part of content that refers to header information at the time of reproduction is decoded and reproduced, it can be decoded and reproduced with reference to the header information held in the buffer area.

  The playback device according to the present invention has a removable memory card having a copyright protection function, and can be used as a portable playback device capable of moving the copyright-protected content to another device so that the content can be played back. Is possible.

It is a figure which shows the structure of the reproducing | regenerating apparatus of this invention. It is a figure for demonstrating the temporary storage process of the encryption content in Embodiment 1 of this invention. It is a figure which shows the example of the file management method in Embodiment 1 of this invention. It is a figure for demonstrating the decoding reproduction | regeneration processing of the encrypted content in Embodiment 1 of this invention. It is a figure for demonstrating the temporary storage process of the encryption content in Embodiment 2 of this invention. It is a figure which shows the structure of the memory card in Embodiment 3 of this invention. It is a figure for demonstrating the decoding reproduction | regeneration processing of the encrypted content in Embodiment 3 of this invention. It is a figure for demonstrating the temporary storage process of the encryption content in Embodiment 4 of this invention. It is a figure which shows the example of the file management method in Embodiment 4 of this invention. It is a figure for demonstrating the decoding reproduction | regeneration processing of the encrypted content in Embodiment 4 of this invention. It is a figure which shows the structure of the conventional reproducing | regenerating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Portable playback device 11 Temporary storage channel 12 Decode channel 13 Analog signal output channel 20 Hard disk 21 Non-secure area of hard disk 22 Encrypted content 30 Memory card 31 Non-secure area of memory card 32 Secure area of memory card 33 Data area 34 Encryption Key management information 35 Encryption key 40 Buffer memory 50 Decoder 100 Portable playback device 111 Temporary storage channel 112 Decode channel 113 Analog signal output channel 114 Data restoration channel 200 Hard disk 210 Non-secure area of hard disk 211 Encrypted content 211a Data block 211b Encryption Chain 300 Memory card 310 Non-secure area of memory card 311 Data area 12 File management information storage area 312a File chain information 312b File head block information 313 Buffer area 313a, 313b Block 314 Time adjustment information storage area 315 Audio content management information 315a Time search table 320 Memory card secure area 321 Encryption key management information 322 Encryption key 400 decoder

Claims (7)

A first recording medium for recording the encrypted content;
A second recording medium having a copyright protection function, in which an encryption key corresponding to the encrypted content is recorded;
A decryption processing unit that decrypts and outputs the encrypted content using the encryption key,
In a playback device for playing back encrypted content recorded on the first recording medium,
The second recording medium has a first-in first-out temporary storage area for temporarily storing all or a part of the encrypted content during decryption and reproduction of the encrypted content, and
File management information for managing encrypted content temporarily stored in the temporary storage area as a file, and a file managed by the file management information and encryption corresponding to the encrypted content temporarily stored in the temporary storage area Encryption key management information that holds the relationship with the encryption key is stored,
The decryption processing unit decrypts all or part of the encrypted content temporarily stored in the temporary storage area using the file management information and the encryption key management information,
The decryption processing unit decrypts and reproduces the encrypted content recorded on the first recording medium, and outputs the decrypted content.
A reproducing apparatus characterized by that. The playback device according to claim 1,
The first-in first-out temporary storage area is composed of fixed-length blocks, and performs input / output of encrypted content in units of blocks,
The file management information includes storage block position identification information for identifying a position of a block group storing encrypted content temporarily stored in the temporary storage area, and encrypted content temporarily stored in the temporary storage area. File name management information that holds the file name in association with the storage block position of the encrypted content,
A reproducing apparatus characterized by that. The playback device according to claim 2,
The storage block position identification information is a FAT in a FAT (File Allocation Table) file system,
The file name management information is a directory.
A reproducing apparatus characterized by that. The playback device according to claim 1,
The encrypted content is decrypted in a fixed-length decryption unit,
The temporary storage area is composed of blocks having a data length that is a multiple of the decoding unit.
A reproducing apparatus characterized by that. The playback device according to claim 1,
The encrypted content has playback time management information that holds the relationship between the playback time and the playback position,
The second recording medium has time adjustment information for adjusting, for each file temporarily stored in the temporary storage area, the reproduction time so as not to deviate based on the reproduction time management information of the encrypted content corresponding to the file. Having
A reproducing apparatus characterized by that. The playback device according to claim 1,
The encrypted content is a header reference type content that refers to header information recorded at the beginning of the content at the time of reproduction,
The second recording medium holds header information of the encrypted content to be played back, and erases the header information of the encrypted content when the playback of the encrypted content ends.
A reproducing apparatus characterized by that. The playback device according to claim 1,
The second recording medium is removable.
A reproducing apparatus characterized by that.

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