JP2007274419A - Content recording method, content moving apparatus, content reproducing method, and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an illegal copy, to prevent reproduction or copy of contents from being unfairly disabled in the case of legal utilization, and to suppress the number of times of rewriting a memory utilized for the prevention a few. <P>SOLUTION: For copy-once contents, a temporary counter provided in a temporary counter storage section 141 is made increment in accordance with the quantity of portions moved to a move destination. A portion preceding to a position corresponding to the value of the temporary counter is disabled to be reproduced and moved. For copy-never contents, a portion preceding to a position corresponding to a value obtained by subtracting a predetermined value from the value of the temporary counter corresponding to a recording time is disabled to be reproduced. The temporary counter is not a binary type but respective bits thereof correspond to a predetermined unit time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a content recording method, a content moving device, a content reproducing method, and these devices for controlling copying of copy once or copy never content.

  Digital image data has been supplied to general viewers by DVD (Digital Versatile Disc) or digital broadcasting. Since digital image data can be copied without deterioration, a copy control system has been introduced from the viewpoint of copyright protection. In the copy control system, copy free, copy once, and copy never are prepared as copy control signals. The user can freely copy copy-free content. In addition, the user can have only one copy of the copy-once content, and when copying the content to another recording medium, the user must delete the content from the original recording medium. Furthermore, the user cannot record the content of the copy never on the recording medium. However, the user is allowed to temporarily record the content on the recording medium in order to time-shift playback the content of the copy never within a range of, for example, 90 minutes.

  In the invention of Patent Document 1, when moving the content, by sequentially attaching a marker to the moved part of the source content, the part once marked is not read again. , Prevent unauthorized copying. However, a device other than a device having a function of not re-reading the marked part can read the marked part, and thus cannot completely prevent unauthorized copying.

  The invention of Patent Document 2 prevents a content stored in a certain flash memory from being stored not only in the flash memory but also in another flash memory via the content database. However, it is not possible to cope with movement to the middle of content or copy never in Copy Once.

  The invention of Patent Document 3 uses a reproducible condition to identify a moved part and an unmoved part in one content, and prohibits the movement of the moved part. However, since the reproducible conditions are stored in the hard disk drive together with the content, unauthorized copying becomes possible by sequentially performing backup of the hard disk drive, movement of the content, and restoration of the hard disk drive.

  In the invention of Patent Document 4, the title key for each content for encrypting / decrypting each content is encrypted with the system key and stored in the encryption area, and the system key is updated when the content is played back Then, the title key is re-encrypted with the updated system key and stored in the encryption area, thereby preventing unauthorized copying of the content due to content backup, content transfer, and content restore. However, the relationship between the system key before update and the system key after update is unknown.

  The inventions of Patent Documents 5 to 8 encrypt content with a different encryption key for each unit block, record the encrypted content on a recording medium, and store the encryption key in a memory provided integrally with the recording medium. Store. However, since this assumes a video tape cassette with a memory IC, if the content is a hard disk drive or a DVD, what is the memory provided integrally with the recording medium? It becomes unknown. Further, according to ARIB, even copy never contents are allowed to be randomly accessed or reproduced multiple times within 90 minutes from the reception, but according to the inventions of Patent Documents 5 to 8. For example, a location that has been played once cannot be played again, and this is disadvantageous to the user.

In addition, according to the inventions of Patent Documents 7 and 8, since the encryption key for encrypting the current block is generated using the plaintext of the previous block, an error is included in the reproduced plaintext. The correct encryption key cannot be restored.
JP 2002-290905 A JP 2001-51906 A JP 2003-272289 A JP 2003-22612 A JP 2003-195751 A JP 2003-195752 A Japanese Patent Laid-Open No. 2003-195753 JP 2003-195754 A

  In the case of copy-once content, it is necessary to prevent the user's moved content from being restored in an easy way. As an easy method, for example, the contents of the entire hard disk are completely backed up, and the moved contents are restored by moving the contents from the hard disk to another recording medium and then restoring the entire hard disk. It exists. In addition, as another easy method, the content moving process is terminated, and the power of the program data of the moving source is intentionally turned off immediately before starting the processing of invalidating the moving source content. There are ways to prevent invalidation processing.

  On the contrary, it is not desirable that the interruption operation unintended by the user is performed. For example, it is not desirable that the moving content is destroyed when a power failure or the like occurs during the movement of the content.

  In addition, in order to perform time-shift reproduction of the copy never content, it is necessary to invalidate the content after a predetermined time has elapsed since recording so that the content cannot be properly reproduced.

  Therefore, it is necessary to prevent illegal copying as described above and prevent improper reproduction or copying of content when used properly.

  In addition, when a flash memory is used to satisfy the above-described necessity, there is a limit to the number of times the flash memory can be rewritten, and this must be taken into consideration. In particular, in a NOR type flash memory, recording is possible in small units such as bits or bytes. However, in order to rewrite the recorded contents, it is necessary to erase the contents and rewrite them. Has a characteristic of being as large as several Kbytes.

  Accordingly, an object of the present invention is to provide a content copy control method and apparatus for preventing illegal copying as described above and preventing unauthorized reproduction or copying of content when used properly. .

  It is another object of the present invention to provide a content copy control method and apparatus capable of preventing the above while suppressing the number of times of rewriting / erasing the memory.

  According to the first aspect of the present invention, an encryption key generating step for generating an encryption key that changes at a predetermined period of content, and a part for each predetermined period of the content is encrypted with an encryption key corresponding to that part An encryption step, a parameter insertion step for inserting a parameter corresponding to an encryption key for each predetermined period of the content into a portion of the content for the predetermined period, and the parameter insertion after being encrypted in the encryption step There is provided a content recording method comprising: a content recording step of recording the content having the parameter inserted therein in a recording medium.

  In the content recording method, the encryption key may be generated using the parameter and an encryption key seed.

  In the content recording method, the parameter corresponding to the encryption key may be a count value.

  According to the second aspect of the present invention, a temporary counter generation step for generating a temporary counter, a temporary counter initialization step for initializing the temporary counter, and initialization of the temporary counter at the start of content movement. A content seek step for seeking the content to a position, and a repetition step for repeating the movement of the content from the initialization position, wherein the repetition step is a parameter reading step for reading a parameter from the content, and a reading at the current repetition If the parameter is different from the parameter read in the previous iteration step, the temporary counter is updated to a value corresponding to the parameter read in the current iteration, and the corresponding predetermined unit portion of the content is further updated. Update that performs processing to enable playback And a step of reading a predetermined unit portion of the content, decrypting the predetermined unit portion with an encryption key generated using the parameters, and outputting the content unit method. .

  In the above content transfer method, the temporary counter includes a number of bits corresponding to the count range, and the initialization of the temporary counter means that the number of bits corresponding to the initialization value is set to the first value and the remaining bits The temporary counter update may be a process of changing one bit from the first value to the second value.

  In the above content transfer method, when the repetition step is completed, a step of storing the count value of the temporary counter in a storage unit and a step of discarding the temporary counter may be further provided.

  In the content transfer method, the temporary counter initialization step may initialize the temporary counter based on a count value currently stored in the storage unit.

  In the above content moving method, if the temporary counter exists at the start of the movement, a temporary count value storing step of storing the count value of the temporary counter in a storage unit, and the position of the count value of the temporary counter And a second content seek step for seeking the content until.

  According to the third aspect of the present invention, a temporary counter generation step for generating a temporary counter, a temporary counter initialization step for initializing the temporary counter, and initialization of the temporary counter at the start of content reproduction. A content seek step for seeking the content to a position after the position; and a repetition step for repeating the reproduction of the content from the position after the seek, wherein the repetition step reads a parameter from the content; and the content And reading out the predetermined unit portion with an encryption key generated using the parameter, and outputting the decrypted unit portion.

  In the content reproduction method, the temporary counter initialization step may initialize the temporary counter with a count value currently stored in the storage unit.

  In the above content reproduction method, if the temporary counter exists at the start of the movement, a temporary count value storing step of storing the count value of the temporary counter in a storage unit, and the position of the count value of the temporary counter A second content seek step for seeking content to a subsequent position may be further included.

  According to the fourth aspect of the present invention, a temporary counter generating means for generating a temporary counter, a temporary counter initializing means for initializing the temporary counter, and initialization of the temporary counter at the start of content recording. Content seek means for seeking content to a position; means for generating an encryption seed; encryption seed storage means for storing the encryption seed in a storage; and internal counter initialization means for setting an internal counter to an initial value; , Encryption key initialization means for generating an encryption key based on the encryption seed and the internal counter of the initial value, first repetition means for repeating the recording of the content from the position of the initialization, and processing of counters And a second counter means for deleting the temporary counter that operates after the operation of the second repeat means. The first repeater is further updated with the internal seed updater for updating the internal counter when the encryption key update timing comes, and with the encryption seed when the encryption key update timing comes An encryption key generating means for generating a new encryption key based on an internal counter, a temporary counter updating means for updating the temporary counter when the timing for updating the encryption key comes, and a content with the current encryption key. Content encrypting means for encrypting, internal counter inserting means for inserting the value of the internal counter into the encrypted content, and content storage for storing the encrypted content into which the internal counter is inserted in the recording medium And the second repeater updates an internal counter that updates the internal counter when an encryption key update timing comes. And means, when came timing of the encryption key update, addition, content recording method characterized by and a second temporary counter updating means for updating the one o'clock counter is provided.

  In the above content recording method, the temporary counter includes a number of bits corresponding to a count range, and the initialization of the temporary counter means that the number of bits corresponding to the initialization value is set to a first value and the remaining bits The temporary counter update may be a process of changing one bit from the first value to the second value.

  In the above content recording method, the number of bits corresponding to the count range of the temporary counter corresponds to a range smaller than the entire range of the content, and an offset counter is provided to compensate for the shortage of the number of bits of the temporary counter. , Further comprising an offset processing means that operates next to each of the temporary counter updating means and the second temporary counter updating means, and the offset processing means initializes the temporary counter and is stored in the encryption key seed storage unit. The count may be changed.

  In the above content recording method, when there is a temporary counter at the start of recording, the content recording method further comprises an internal count value setting means for setting the count value of the temporary counter as an internal count value. The encryption key generation means may be operated later.

  In the above content recording method, the number of bits corresponding to the count range of the temporary counter corresponds to a range smaller than the entire range of the content, and an offset counter is provided to compensate for the shortage of the number of bits of the temporary counter. In the internal count value setting means that uses the count value of the temporary counter as the internal count value, the value of the offset counter may be added to the internal counter value.

According to the fifth aspect of the present invention, at the start of recording, a temporary counter generating means for generating a temporary counter, a temporary counter initializing means for initializing the temporary counter, and a position for initializing the temporary counter. Content seek means for seeking content, means for generating an encryption seed, encryption seed storage means for storing the encryption seed in an encryption key seed storage unit, and internal counter initialization means for initializing an internal counter An encryption key initialization means for generating an encryption key based on the encryption seed and the internal counter of the initial value, a first repetition means for repeating the recording of the content from the initialization position, Second repeating means for repeating the process; and temporary counter deleting means for deleting the temporary counter that operates after the operation of the second repeating means. The first repeating means includes a means for setting a value of an elapsed counter indicating an elapsed time of content in the internal counter when an encryption key update timing has come, and an encryption key update timing, Obtained by dividing the internal counter by the number of bits of the temporary counter as the temporary count value, and when the encryption key update timing comes, further dividing the internal counter by the number of bits of the temporary counter Means that uses the value obtained by multiplying the integer value by the number of bits of the temporary counter as an offset value, and when the encryption key update timing arrives, a new cipher is created based on the encryption seed and the updated internal counter. An encryption key generation means for generating a key; a content encryption means for encrypting content with the current encryption key; and a value of the internal counter for the encrypted content. An internal counter insertion means for entering,
Content storing means for storing the encrypted content with the internal counter inserted in a recording medium, and the second repeating means indicates the elapsed time of the content when the timing of updating the encryption key comes A means for setting a value of an elapsed counter in the internal counter; a means for setting a remainder obtained by dividing the internal counter by the number of bits of the temporary counter when the timing for updating the encryption key comes; And means for setting an offset value to a value obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and rounding it down when the update timing comes. A content recording method is provided.

  In the above content recording method, the temporary counter includes a number of bits corresponding to a count range, and the initialization of the temporary counter means that the number of bits corresponding to the initialization value is set to a first value and the remaining bits The temporary counter update may be a process of changing one bit from the first value to the second value.

  In the above content recording method, means for setting a value of an elapsed counter indicating an elapsed time of the content in the internal counter when an encryption key update timing comes when a temporary counter exists at the start of the recording; When the encryption key update timing comes, further, a means for setting the remainder obtained by dividing the internal counter by the number of bits of the temporary counter as the temporary count value; and when the encryption key update timing comes, Means for multiplying the integer value obtained by dividing by dividing by the number of bits of the temporary counter and the number of bits of the temporary counter as an offset value, and after the operation of these means, the encryption key The generation means may operate.

  According to a sixth aspect of the present invention, there is a period that starts when content recording starts and ends when a predetermined time elapses after the content recording ends, in which the start of the content starts. The content playback means operates only when a temporary counter that represents the elapsed time from the actual time is presently present, and the content playback means includes a temporary count read means for reading the count value of the temporary counter, and the read temporary count value If the count value inserted at the current position of the content is less than a value obtained by subtracting the count corresponding to the time shift allowable time from the internal count value, the content The count value inserted at the current position corresponds to the time shift allowable time from the internal count value Until the value is reduced by a certain count, the seek means for seeking the content, the count reading means for reading the count value from the current position of the content, and decrypting the content using the count value, There is provided a content reproduction method comprising content output means for outputting subsequent content.

  In the above content reproduction method, the entire range of the content cannot be handled only by the temporary counter, and the internal count value setting means can use the internal count value for the read temporary count value. A content reproduction method characterized in that a value obtained by adding an offset value corresponding to a certain number of times is used as the internal count value.

  According to the seventh aspect of the present invention, when the recorded content is once transferred, the first value is changed to the second value according to the amount from the start point of the content to the current transfer location. There is provided a copy-once content control method characterized by changing the cumulative number of bits and prohibiting reproduction and re-transmission of a portion before the portion corresponding to the cumulative number of bits.

  In the copy-once content control method, the cumulative number of bits changed by storing the bits in a nonvolatile memory and reading the bits from the nonvolatile memory even after the transfer is interrupted. So that the reproduction and transfer of the portion before the portion corresponding to the cumulative number of bits may be prohibited.

  According to the eighth aspect of the present invention, once content is recorded, the accumulation of bits changed from the first value to the second value according to the amount from the start point of the content to the current recording location. There is provided a method for time-shifted reproduction of copy never content, wherein the number is changed and reproduction of a portion of a predetermined time before the portion corresponding to the cumulative number of bits is prohibited.

  In the above-described method for time-shift reproduction of copy never content, the bit may be stored in a nonvolatile memory.

  According to the present invention, an encryption key generating step for generating an encryption key that changes for each predetermined period of content, and an encryption step for encrypting a part for each predetermined period of the content with an encryption key corresponding to that part, , The parameter corresponding to the encryption key for each predetermined period of the content is inserted into the part of the predetermined period of the content, the parameter is encrypted in the encryption step, and the parameter is And a content recording step of recording the inserted content on a recording medium. Therefore, it is possible to perform copy-once control using the parameters.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

[Embodiment 1]
The configuration of a copy control-compatible content recording / reproducing apparatus for recording copy-once content will be described with reference to FIG.

  The recording medium 101 stores content processed by the encryption unit 105. The recording medium 101 is, for example, a hard disk drive.

  The input unit 103 inputs content, reads time information from the content, and measures the capacity of the content up to now.

  The encryption unit 105 encrypts the content supplied from the input unit 103 using the encryption key stored in the encryption key storage unit 117, and embeds the value of the internal counter 115a in the content. For example, if the content is in MPEG format, a counter value is embedded in the private stream at the beginning of the GOP.

  The encryption key seed generation unit 111 generates an encryption key seed using a random number or the like.

  The encryption key seed storage unit 113 stores the encryption key seed and the counter value.

  The encryption key seed storage unit 113 is provided in the nonvolatile memory 131. As the nonvolatile memory, for example, a flash EEPROM or the like is used.

  The counter management unit 115 performs processing related to the counter, and also has its own counter (hereinafter referred to as “internal counter”, denoted by reference numeral 115a).

  The encryption key storage unit 117 stores the encryption key generated by the encryption key generation unit 121.

  The encryption key storage unit 117 is normally provided in a volatile memory 135 such as a RAM, but may be provided in a nonvolatile memory.

  The decryption unit 107 reads the encrypted content from the recording medium 101 and the count added thereto, and decrypts the content using the encryption key generated by the encryption key generation unit 121 from this count and the encryption key seed. I do.

  The output unit 109 outputs the decrypted content to a monitor or the like in the case of reproducing the content, and in the case of moving the content, encrypts the decrypted content once again by some method, Is output to the content recording side device.

  The operation of the copy control-compatible content recording / playback apparatus when recording copy-once content will be described with reference to FIG.

  First, the encryption key seed generation unit 111 generates an encryption key seed (step S201) and stores it in the encryption key seed storage unit 113 (step S203).

  Next, the counter management unit 115 initializes the value of the internal counter 115a to zero (step S205) and stores it in the encryption key seed storage unit 113 (step S207).

  Next, the encryption key generation unit 121 generates the first encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the zero value held by the internal counter 115a (step S209). ). The generated encryption key is stored in the encryption key storage unit 117.

  Next, the count update timing detection unit 123 refers to the time information of the content obtained from the input unit 103, and determines whether or not the current timing is a timing for updating the encryption key (step S211). The timing for updating the encryption key is, for example, every minute. In such a case, the encryption key is updated every minute. However, the update timing may be a timing for each other period, a timing for each predetermined capacity of the content, or the like.

  If the current timing is the timing for updating the encryption key (YES in step S211), the process proceeds to step S213, and if not, the process proceeds to step S217.

  In step S213, the counter management unit 115 increases the value of the internal counter 115a by 1. Next, the encryption key generation unit 121 generates a new encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the value of the internal counter 115a increased in step S213 (step S215). ). The generated encryption key is stored in the encryption key storage unit 117. From step S215, the process proceeds to step S217.

  In step S 217, the encryption unit 105 encrypts the content input from the input unit 103 using the encryption key currently stored in the encryption key storage unit 117.

  Next, the encryption unit 105 embeds the counter value currently stored in the internal counter 115a in the content (step S219).

  In step S217 and step S219, the encrypted content into which the count value is inserted is stored in the recording medium 101.

  Next, it is determined whether or not the recording should be terminated (step S221). If so, the recording is terminated. If not, the process returns to step S211 to continue the recording.

  As a result, the content stored in the recording medium 101 is encrypted with the encryption key generated based on the encryption key seed and the counter value updated at predetermined intervals (for example, every minute), and The counter value is embedded.

  Also, the encryption key seed storage unit 113 stores the encryption key seed and a count value of zero. These are stored in the encryption key seed storage unit 113 in association with the content identification information.

  Next, the operation of the copy control-compatible content recording / playback apparatus when moving copy-once content will be described with reference to FIG.

  First, the counter management unit 115 determines whether or not a temporary counter corresponding to the content exists in the counter temporary storage unit 141 (step S231). In order to make this determination, if a temporary counter is provided, the corresponding content identification information is associated with the temporary counter. If the temporary counter associated with its own identification information is in the counter temporary storage unit 141, the result in step S231 is affirmative, and otherwise, the result in step S231 is negative.

  If there is no temporary counter corresponding to the content in counter temporary storage unit 141 (NO in step S231), counter management unit 115 provides a temporary counter corresponding to the content in counter temporary storage unit 141, and the temporary counter Is initialized.

  Here, the counter temporary storage unit 141 is provided in the nonvolatile memory 131 in the same manner as the encryption key seed storage unit 113. As the nonvolatile memory, for example, a flash EEPROM or the like is used.

  The count value stored in the encryption key seed storage unit 113 and the count value counted by the internal counter 115a are usually encoded in binary. In contrast, the count value of the temporary counter provided in the counter temporary storage unit 141 is in a decoded state. For example, if the content is a two-hour movie and the encryption key is updated every minute, it is necessary to count from zero to 119. For this purpose, the temporary counter is configured with 120 bits so that one bit corresponds to one minute. In particular, in consideration of the case where the nonvolatile memory is a NOR type flash EEPROM, when a temporary counter corresponding to the content is newly provided and initialized, a 120-bit area is first removed from the nonvolatile memory. Secure it, associate it with the content, and initialize all 120 bits to 1. As will be described later, when the temporary counter is updated, the value of the bit is changed from 1 to zero sequentially. For example, in the initial state, the temporary counter is “11... 1” (all 1), but when the movement has elapsed for 1 minute, the temporary counter becomes “011. When one minute has elapsed, the temporary counter becomes “001... 1”. Such updating is continued until the temporary counter reaches “000... 0” (all zeros) at the end of the content.

  If the temporary counter represents a numerical value encoded in binary, the number of rewrites of the nonvolatile memory increases. On the other hand, according to the present invention, the number of rewrites can be reduced by setting the temporary counter as described above.

  However, if the movement of content is normally interrupted without moving the content to the end of the content, the process proceeds from step 247 to step S249 and step S251 described later. In this case, if the temporary counter is discarded in step S251, the determination result in step S231 is negative, and the process proceeds to step S233. In this case, initialization of the temporary counter in step S233 is initialization using the count value currently stored in the encryption key seed storage unit 113. This involves binary decoding. That is, the count value stored in binary number in the encryption key seed storage unit 113 is decoded to the number of bits of zero, and the decoding result is set in the temporary counter. The count value currently stored in the encryption key seed storage unit 113 is the count value stored in the encryption key seed storage unit 113 in the previous step S249.

  Returning to the flowchart, after step S233, the process proceeds to step S234, where the content is seeked to the initialization position. That is, the fast-forwarding of the content is continued until the count value added to the content matches the initialization value of the temporary counter. Of course, in the case of starting the movement of the content, since the initialization value of the temporary counter is zero, the content position remains at the head position.

  On the other hand, if there is a temporary counter corresponding to the content in the counter temporary storage unit 141 (YES in step S231), the counter management unit 115 counts the temporary counter corresponding to the content in the counter temporary storage unit 141. Is stored in the encryption key seed storage unit 113 (step S235). At this time, the number of zero bits of the temporary counter is encoded into a binary number, and the result of the encoding is stored in the encryption key seed storage unit 113. The update of the count value stored in the encryption key seed storage unit 113 by storing the count value of the temporary counter in the encryption key seed storage unit 113 in step S235 will be described later. Will be prohibited from playing.

  Next, the content seeks to the position of the counter value (step S236). For this purpose, the fast-forwarding of the content is continued until the count value added to the content matches the count value of the temporary counter. YES in step S231 is a case where the movement of the content is interrupted without restarting through steps S249 and S251 for some reason and is resumed. Some reasons include, for example, suspension of movement due to a sudden power outage, unauthorized unauthorized power interruption by a malicious person, and the like. This will be referred to as “abnormal interruption”. It is undefined which step is performed during abnormal interruption. Therefore, when an abnormal interruption occurs, steps S249 and S251 are not performed and the temporary counter remains. In such a case, in the copy-once content, the part before the position where the movement is interrupted cannot be moved again. By executing step S236, this second movement can be prohibited.

  The process proceeds from step S234 or step S236 to step S237.

  In step S237, the count value is read from the content. This reading includes reading video / audio of the content corresponding to the count value.

  Next, it is determined whether or not the count value read from the content has been updated this time (step S239). That is, it is determined whether or not the count value read from the content in the current iteration step S237 is different from the count value read from the content in the previous iteration step S237.

  If the counter value is updated every minute during recording, the determination result in step S239 becomes affirmative for every minute of content.

  If the determination result in step S239 is negative, the content read in step S237 is output to the recording side device without going through steps S241 and S243 (step S245).

  In step S245, the following is performed.

  The encryption key generation unit 121 generates an encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the count value read from the content, and stores this in the encryption key storage unit 117. . The decryption unit 107 decrypts the content read from the recording medium 101 using the encryption key stored in the encryption key storage unit 117. The output unit 109 re-encrypts the content by a method corresponding to the recording-side device and outputs it to the recording-side device so that the content is not output in the decrypted state.

  If the determination result in step S239 is positive, the temporary counter is updated (step S241). This update is, for example, such that the bit pattern of the temporary counter is changed from “0011... 1” to “0001.

  Next, a process for enabling the reproduction of the content output to the recording side device from the time when the previous step S243 is executed to the time when the current step S243 is executed is performed (step S243). By this enabling process, the content recorded by the recording side device can be reproduced for the first time.

  From step S243, the process proceeds to step S245. Step S245 has already been described.

  From step S245, the process proceeds to step S247. In step S247, it is determined whether or not the movement has been completed or the normal interruption has been performed. The end of movement is the end of movement to the end of the content. Further, the normal interruption is an interruption due to a legitimate operation of a user who has decided to stop the movement so far, an interruption due to the start of use of the recording apparatus for other purposes, or the like. Normal interruption is distinguished from abnormal interruption.

  If the determination result in step S247 is negative, the process returns to step S237 to continue moving the content.

  If the determination result in step S247 is affirmative, the current count value of the temporary counter in the counter temporary storage unit 141 is stored in the encryption key seed storage unit 113 (step S249). At this time, the bit pattern of the temporary counter is converted into a binary number, and the result of this conversion is stored in the encryption key seed storage unit 113. Thereby, the count value stored in the encryption key seed storage unit 113 is updated. By doing this, in the initialization of the temporary counter in step S233, the temporary counter is initialized to a value corresponding to the position where the movement is interrupted. As a result, the movement can be resumed from the interruption position after the movement is interrupted.

  Next, the temporary counter corresponding to the content is discarded from the temporary counter storage unit 141. Here, discarding is a process of making an access impossible by initializing an area reserved for a temporary counter, such as flushing the area.

  In addition, when it progresses to step S249 by normal interruption by step S247, you may abbreviate | omit step S251. In this case, the temporary counter remains in the counter temporary storage unit 141. Then, when the movement of the content is resumed, the determination result in step S231 becomes affirmative. However, since the initialization in step S233 is as described above, the state is the same when the process proceeds to step S237.

  Next, the operation of the copy control-compatible content recording / playback apparatus when moving copy-once content will be described with reference to FIG.

  If the entire copy-once content is not moved to the destination, the entire content can be reproduced any number of times. On the other hand, when a part of the copy-once content is moved to the destination, reproduction of the moved part must be prohibited.

  Steps S261, S263, S267, S271, S275, and S277 shown in FIG. 4 correspond to Steps S231, S233, S234, S235, S236, and S237 shown in FIG. Only the differences will be described.

  Next to step S263, it is determined whether or not the reproduction start position desired by the user is before the position corresponding to the initial value of the temporary counter set in step S263 (step S265).

  If this is the case (YES in step S265), starting playback from the playback start position desired by the user is against the copy-once rule, so the process proceeds to step S267, where the setting is made in step S263. The content reading is advanced to a position corresponding to the initial value of the temporary counter.

  Otherwise (NO in step S265), starting playback from the playback start position desired by the user does not violate the copy-once rule, so the process proceeds to step S269, where the playback start position desired by the user is reached. Advance content.

  On the other hand, after step S271, it is determined whether or not the reproduction start position desired by the user is before the position corresponding to the count value of the temporary counter viewed in step S271 (step S273).

  If so (YES in step S273), starting playback from the playback start position desired by the user violates the copy-once rule, so the process proceeds to step S275, where it was seen in step S271. The content reading is advanced to a position corresponding to the count value of the temporary counter.

  If not (NO in step S273), starting playback from the playback start position desired by the user does not violate the copy-once rule, so the process proceeds to step S269, where the playback start position desired by the user is reached. Advance content.

  From step S267, S269 or S275, the process proceeds to step S277, where the reproduction of the content is started.

  In step S279, the following is performed.

  The encryption key generation unit 121 generates an encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the count value read from the content, and stores this in the encryption key storage unit 117. . The decryption unit 107 decrypts the content read from the recording medium 101 using the encryption key stored in the encryption key storage unit 117. The output unit 109 outputs the decrypted content to the output device.

  From step S279, the process proceeds to step S281. In step S281, it is determined whether or not the reproduction end or the normal interruption of the reproduction has been performed. The end of playback is the end of playback to the end of the content. Also, the reproduction interruption is the end of reproduction to the middle of the content.

[Embodiment 2]
Next, the operation of the copy control compatible content recording / reproducing apparatus when recording the content of the copy never for time shift reproduction will be described with reference to FIG. 5 and FIG.

  In time-shifted playback, each part of the content must be playable within a predetermined time (for example, 90 minutes) after it is received, but playback is prohibited if more time has passed. And shall be.

  First, the counter management unit 115 determines whether or not a temporary counter exists in the counter temporary storage unit 141 (step S301).

  If this determination result is affirmative (YES in step S301), this means that recording for time-shift playback has been abnormally interrupted. The counter management unit 115 reads the temporary count value of the temporary counter from the counter temporary storage unit 141 (step S315), reads the offset count value from the encryption key seed storage unit 113 (step S317), and sets the temporary count value and the offset count value. Is set in the internal counter 115a. The offset count value will be described later. At this time, the value set in the internal counter corresponds to the elapsed time at the time of abnormal interruption. For example, if the counter is incremented by 1 every minute, an abnormal interruption occurs 10 minutes after the start of recording for time-shifted reproduction, and the process enters step S301 after 5 minutes, Since the temporary count value is 10 and the offset count value is 0, 10 + 0 = 10 is set in the internal counter. Also, when the temporary count value range is 0 to 63 and the offset count value is 0, 64, 128,..., Abnormal interruption occurs 110 minutes after the start of recording for time shift playback. When the process enters step S301 after 5 minutes, the temporary count value is 46 and the offset count value is 64, so 46 + 64 = 110 is set in the internal counter.

  If there is no temporary counter in the temporary counter storage unit 141 (NO in step S301), this means that the time shift reproduction has not been abnormally interrupted. That is, it means that recording for time shift reproduction starts from now on.

  In this case, a temporary counter corresponding to the content is provided in the temporary counter storage unit 141, and all bits of the temporary counter are initialized to 1. That is, if it is expressed in binary or decimal instead, the value of the temporary counter is initialized to zero (step S303). Next, the content seeks to the initialization position (step S305).

  Next, the encryption key seed generation unit 111 generates an encryption key seed (step S307) and stores it in the encryption key seed storage unit 113 (step S309).

  Next, the counter management unit 115 initializes the internal counter 115a to zero (step S311), and stores this value in the encryption key seed storage unit 113 (step S313).

  Referring to FIG. 6, from step S313 or step S319, the process proceeds to step S320.

  In step S320, the encryption key generation unit 121 determines an initial encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the value of the internal counter 115a initialized to zero in step S311. Generate. The generated encryption key is stored in the encryption key storage unit 117.

  In step S321, the count update timing detection unit 123 refers to the content time information obtained from the input unit 103, and determines whether or not the current timing is a timing for updating the encryption key (step S321). . The timing for updating the encryption key is, for example, every minute.

  If the current timing is the timing for updating the encryption key (YES in step S321), the process proceeds to step S323, and if not, the process proceeds to step S331.

  In step S323, the counter management unit 115 increases the value of the internal counter 115a by 1. Next, the encryption key generation unit 121 generates a new encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the value of the internal counter 115a increased in step S323 (step S325). ). The generated encryption key is stored in the encryption key storage unit 117.

  Next, the temporary counter is updated (step S327). In this update, the currently focused bit (a bit adjacent to zero and having a value of 1) is set to zero. By doing so, for example, the temporary counter changes from “0011... 11” to “0001.

  Next, an offset process is performed (step S329). Here, offset processing will be described. For example, when the number of bits of the temporary counter is 64 and the counter is updated every minute, the temporary counter can handle content having a length of 64 minutes or less. However, content with a time exceeding 64 minutes cannot be handled with only a temporary counter. Therefore, when the content time exceeds 64 minutes, the temporary counter whose current value is all zeros is changed to all ones (“000... 0” (64 bits are all zeros). .. 1 ”(all 64 bits are 1)), and the count value stored in the encryption key seed storage unit 113 is increased by 64. For example, at the 64 minute portion of the content, the temporary counter is “000... 0” (all 64 bits are zero), and the count value stored in the encryption key seed storage unit 113 is zero. When the content advances to 65 minutes, the temporary counter is initialized to “111... 1” (64 bits are all 1), and the count value stored in the encryption key seed storage unit 113 is Set to 1. Similarly, at the 128-minute portion of the content, the temporary counter is “000... 0” (64 bits are all zero), and the count value stored in the encryption key seed storage unit 113 is 1. However, when the content advances to 129 minutes, the temporary counter is initialized to “111... 1” (64 bits are all 1), and the count value stored in the encryption key seed storage unit 113 Set to 2.

  By performing such an offset process, it is possible to grasp the elapsed time of the content by using the offset value stored in the temporary counter and the encryption key seed storage unit 113 (adding both). This calculation method is used in step S319 described above.

  From step S321 or step S329, the process proceeds to step S331.

  In step S <b> 331, the encryption unit 105 encrypts the content input from the input unit 103 using the encryption key currently stored in the encryption key storage unit 117 and stores the encrypted content in the recording medium 101.

  Next, the encryption unit 105 embeds the counter value currently stored in the internal counter 115a in the content (step S333).

  In step S331 and step S333, the encrypted content into which the count value is inserted is stored in the recording medium 101.

  Next, it is determined whether or not the recording should be terminated (step S335). If so, the recording is terminated. If not, the process returns to step S321 and the recording is continued.

  After the recording is completed, the same operation as in steps S321 to S335 is continued for only the counter for the time shiftable period.

  That is, if the determination in step S335 is affirmative, it is determined whether or not the current time is the encryption key update timing if the encryption key update is continued (step S321B). In the above example, the determination result in step S321B becomes positive every time 1 minute elapses.

  If the determination result in step S321B is affirmative, the internal counter 115a is updated by 1 (step S323B), the temporary counter is updated (step S327B), and offset processing is performed (step S329B).

  If the determination result of step S321B is negative, the process proceeds to step S335B. The process proceeds from step S329B to step S335B.

  In step S335B, it is determined whether or not a time shiftable period has elapsed since the recording of the content ended.

  If it has not yet elapsed (NO in step S335B), the process returns to step S321B.

  If it has elapsed, the temporary counter is deleted from the temporary counter storage unit 141 (step S337), and the encryption key seed and count are deleted from the encryption key seed storage unit 113 (step S339).

  As a result, the content stored in the recording medium 101 is encrypted with the encryption key generated based on the encryption key seed and the counter value updated at predetermined intervals (for example, every minute), and The counter value is embedded.

  In addition, the encryption key seed storage unit 113 stores the encryption key seed and the offset value. These are stored in the encryption key seed storage unit 113 in association with the content identification information.

  The sum of the temporary counter value and the offset value represents the recording duration.

  Next, a description will be given of an operation example in the case where there is no interruption of recording. Steps S321 to S335 are repeated until content recording is completed. In the repetition, for example, steps S323 to S329 are executed every minute.

  If there is a recording interruption, first, the process proceeds from step S301 to step S303, and then proceeds to step S321. Steps S321 to S335 are repeated, but recording is interrupted at a certain repetition. When resuming the recording, the process proceeds from step S301 to step S315, and after executing steps S315 to S319, the process proceeds to step S320. Steps S321 to S335 are repeated again until the content recording is completed. In the repetition, for example, steps S323 to S329 are executed every minute.

  Next, the operation of the copy control-compatible content recording / reproducing apparatus when the content of the copy never is time-shifted reproduced will be described with reference to FIG.

  First, the counter management unit 115 determines whether or not there is a temporary counter corresponding to the content in the counter temporary storage unit 141 (step S340).

  If it does not exist (NO in step S340), since the time shift allowable time has already elapsed even from the end of the content, the processing is stopped.

  If it exists (YES in step S340), the current value of the temporary counter is read from the counter temporary storage unit 141 (step S341). Next, the counter management unit 115 reads the current offset value from the encryption key seed storage unit 113 (step S343). Next, the counter management unit 115 stores the value obtained by adding the value of the temporary counter read in step S341 and the offset value read in step S343 in the internal counter 115a (step S345). As a result, when there is no recording interruption, the value of the internal counter 115a represents the current elapsed time from the start of content recording.

  Next, the decryption unit 107 obtains the count value embedded at the current position of the content in the recording medium 101 by subtracting the value corresponding to the time shift allowable time (for example, 90 minutes) from the value of the internal counter 115a. The content is advanced until the value becomes equal to or greater than the specified value (steps S347 and S349). From the beginning, if the count value embedded in the current position of the content in the recording medium 101 is equal to or greater than the value obtained by subtracting the value corresponding to the time shift allowable time (for example, 90 minutes) from the value of the internal counter 115a. There is no case of returning from step S349 to step S347.

  After the content is advanced as necessary, the content reproduction from step S351 to step S355 is started.

  In step S351, the decryption unit 107 reads the count value from the content.

  In step S353, the encryption key generation unit 121 generates an encryption key based on the encryption key seed stored in the encryption key seed storage unit 113 and the count value read from the content, and uses this to generate the encryption key storage unit. 117 is stored. The decryption unit 107 decrypts the content read from the recording medium 101 using the encryption key stored in the encryption key storage unit 117. The output unit 109 outputs the decrypted content to the output device.

  From step S353, the process proceeds to step S355. In step S355, it is determined whether or not playback has been completed or playback has been interrupted. The end of playback is the end of playback to the end of the content. Also, the reproduction interruption is the end of reproduction to the middle of the content.

  This operation will be described by taking as an example a case where one count corresponds to one minute, the content time is 120 minutes, the time shift allowable time is 90 minutes, and recording is not interrupted.

  If the value of the internal counter is 5, the current elapsed time from the start of content recording is 5 minutes. In this case, immediately after executing step S347 and step S349 for the first time, the process proceeds to step S351. Therefore, time shift playback starts from the beginning of the content. That is, time-shifted reproduction is performed with a delay of 5 minutes from the initial position of the content.

  If the value of the internal counter is 100, the current elapsed time from the start of content recording is 100 minutes. In this case, the content position is advanced to a position of 100−90 = 10 minutes in steps S347 and S349, and then the process proceeds to step S351. Therefore, time-shifted playback is performed with a 90-minute delay from the 10-minute position of the content.

  If a temporary counter exists and the value of the internal counter is 150, the current elapsed time from the start of content recording is 150 minutes. In this case, the content position is advanced to a position of 150-90 = 60 minutes in steps S347 and S349, and then the process proceeds to step S351. Therefore, time-shifted reproduction is performed with a 90-minute delay from the 60-minute position of the content.

  If the current elapsed time from the start of content recording exceeds 210 minutes, there is no temporary counter. Therefore, it is impossible to perform time shift reproduction.

[Embodiment 3]
In the second embodiment, if the recording is abnormally interrupted while the content is being recorded for time shift reproduction, the time shift allowable amount of the content recorded after that will increase.

  The third embodiment eliminates this drawback, and even if the recording is abnormally interrupted during the recording of the content for the time shift reproduction, the time shift allowable amount of the content recorded thereafter is not reduced. It is to prevent it from increasing.

  FIG. 8 shows the configuration of the third embodiment. A difference from the first embodiment shown in FIG. 1 is that a progress counter 143 is added.

  The elapsed counter 143 measures the elapsed time from the start of the content to the present. A counter may be provided inside, or a time stamp of content input by the input unit 103 may be referred to.

  The recording operation described with reference to FIG. 5 in the second embodiment is replaced with that shown in FIG. 9, and the reproducing operation described with reference to FIG. 6 in the second embodiment is the same as that shown in FIG. Replace.

  The operation shown in FIG. 9 is different from the operation shown in FIG. 5 in that steps S315, S317, and S319 are replaced with steps S363, S365, and S367.

  In step S363, the value of the progress counter 143 is set in the internal counter 115a. In step S365, the remainder obtained by dividing the value of the internal counter by an offset unit (for example, a unit of 64 corresponding to 64 minutes) is set as a temporary count value provided in the counter temporary storage unit 141. In step S367, a value obtained by dividing the value of the internal counter by the offset unit and rounding it down is multiplied by the offset unit, and the value is stored in the encryption key seed storage unit 113.

  For example, if the value of the progress counter 143 is 100 and the offset unit is 64, the value of the temporary counter is 36 and the offset value is 64.

  The operation shown in FIG. 10 differs from the operation shown in FIG. 6 in that steps S323, S325, S327, and S329 are replaced with steps S369, S371, S373, and S375.

  Steps S369, S371, and S373 are the same as steps S363, S365, and S367, respectively, shown in FIG.

  Step S375 is the same as step S325. Here, the encryption key generation unit 121 uses the encryption key seed stored in the encryption key seed storage unit 113 and the value of the internal counter 115a set in step S363. In addition, a new encryption key is generated.

  Steps S377, S379, and S381 are the same as steps S363, S365, and S367, respectively, shown in FIG.

  Note that changing the temporary counter provided in the temporary counter storage unit 141 from 1 to 0 bit by bit and increasing the count value of the internal counter or the count value in the encryption key seed storage unit 113 by 1 are associated with each other. As described above, the temporary counter provided in the temporary counter storage unit 141 is changed bit by bit from 1 to zero, and the count value of the internal counter and the count value in the encryption key seed storage unit 113 are decreased by 1. You may associate. In addition, as long as the one-to-one correspondence with the temporary counter is maintained, a counter other than a counter that is incremented or decremented by one in binary may be used as the internal counter 115a. For example, a counter that sequentially counts binary numbers that have a one-to-one correspondence with all bit patterns that can actually occur in the temporary counter may be used as the internal counter 115a. For example, a gray code counter may be used as the internal counter 115a.

  1 and 8 can be realized by hardware, software, or a combination thereof.

1 is a block diagram illustrating a configuration of a copy control-compatible content recording / reproducing apparatus according to Embodiments 1 and 2 of the present invention. FIG. 4 is a flowchart showing a method for recording copy-once content in the first embodiment of the present invention. 6 is a flowchart illustrating a method for moving copy-once content in the first embodiment of the present invention. 4 is a flowchart illustrating a method for reproducing copy-once content in the first embodiment of the present invention. It is a flowchart (1/2) which shows the method of recording the content of a copy never for time shift reproduction in Embodiment 2 of this invention. It is a flowchart (2/2) which shows the method of recording the content of a copy never for time shift reproduction in Embodiment 2 of this invention. It is a flowchart which shows the method of carrying out time shift reproduction | regeneration of the content of a copy never in Embodiment 2 of this invention. It is a block diagram which shows the structure of the content recording / reproducing apparatus corresponding to copy control by Embodiment 3 of this invention. It is a flowchart (2/2) which shows the method to record the content of a copy never for time shift reproduction in Embodiment 3 of this invention. It is a flowchart which shows the method of carrying out the time shift reproduction of the content of a copy never in Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Recording medium 103 Input part 105 Encryption part 107 Decryption part 109 Output part 111 Encryption key seed generation part 113 Encryption key seed storage part 115 Counter management part 115a Internal counter 117 Encryption key storage part 121 Encryption key generation part 131 Non-volatile memory 135 Volatile Memory 141 Counter Temporary Storage Unit 143 Progress Counter

Claims (34)

An encryption key generation step of generating an encryption key that changes at predetermined intervals of the content;
An encryption step of encrypting a portion for each predetermined period of the content with an encryption key corresponding to the portion;
A parameter insertion step of inserting a parameter corresponding to an encryption key for each predetermined period of the content into a portion of the content for the predetermined period;
A content recording step of recording the content encrypted in the encryption step and the parameter inserted in the parameter insertion step on a recording medium;
A content recording method comprising: The content recording method according to claim 1,
The content recording method, wherein the encryption key is generated using the parameter and an encryption key seed. The content recording method according to claim 1,
The content recording method, wherein the parameter corresponding to the encryption key is a count value. A temporary counter generation step for generating a temporary counter at the start of content movement;
A temporary counter initialization step for initializing the temporary counter;
A content seek step for seeking the content up to the initialization position of the temporary counter;
Repeating the movement of the content from the initialization position, and
The repeating step includes
A parameter reading step for reading parameters from the content;
If the parameter read in the current iteration is different from the parameter read in the previous iteration step, the temporary counter is updated to the value corresponding to the parameter read in the current iteration, and further the correspondence of the content An update step for performing processing for enabling reproduction of the predetermined unit portion to be performed;
Reading a predetermined unit portion of the content, decrypting the predetermined unit portion with an encryption key generated using the parameters, and outputting the decrypted unit portion;
A content moving method comprising: In the content movement method of Claim 4,
The temporary counter includes a number of bits corresponding to a count range,
The initialization of the temporary counter is a process of setting the number of bits corresponding to the initialization value to the first value and the remaining bits to the second value,
The updating of the temporary counter is a process of changing one bit from a first value to a second value. In the content movement method of Claim 5,
If the repetition step is completed, storing the count value of the temporary counter in a storage unit;
Discarding the temporary counter;
A content moving method, further comprising: The content moving method according to claim 6,
In the temporary counter initialization step, the temporary counter is initialized based on a count value currently stored in the storage unit. In the content movement method of Claim 4,
If the temporary counter is present at the start of the move,
A temporary count value storing step of storing the count value of the temporary counter in a storage unit;
A second content seek step for seeking the content to the position of the count value of the temporary counter;
A content moving method, further comprising: A temporary counter generation step for generating a temporary counter at the start of content playback;
A temporary counter initialization step for initializing the temporary counter;
A content seek step for seeking the content up to a position after the initialization position of the temporary counter;
A repeating step of repeating playback of the content from a position after seeking;
With
The repeating step includes
A parameter reading step of reading parameters from the content;
Reading out a predetermined unit portion of the content, decrypting the predetermined unit portion with an encryption key generated using the parameter,
A content reproduction method comprising: The content playback method according to claim 9, wherein
In the temporary counter initialization step, the temporary counter is initialized based on the count value currently stored in the storage unit. The content playback method according to claim 9, wherein
If the temporary counter is present at the start of the move,
A temporary count value storing step of storing the count value of the temporary counter in a storage unit;
A second content seek step for seeking content to a position after the position of the count value of the temporary counter;
The content reproduction method further comprising: Temporary counter generating means for generating a temporary counter at the start of recording of content;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking content up to the initialization position of the temporary counter;
Means for generating an encryption seed;
Encryption seed storage means for storing the encryption seed in a storage unit;
An internal counter initialization means for initializing the internal counter;
Encryption key initializing means for generating an encryption key based on the encryption seed and the internal counter of the initial value;
First repeating means for repeating the recording of the content from the initialization position;
A second repeating means for repeating the processing of the counters;
Temporary counter deleting means for deleting the temporary counter operating after the operation of the second repeating means;
With
The first repeating means includes
An internal counter updating means for updating the internal counter when the timing of encryption key update comes;
Encryption key generation means for generating a new encryption key based on the encryption seed and the updated internal counter when the timing of encryption key update comes,
A temporary counter update means for updating the temporary counter when an encryption key update timing comes;
Content encryption means for encrypting content with the current encryption key;
Internal counter insertion means for inserting the value of the internal counter into the encrypted content;
Content storage means for storing the encrypted content into which the internal counter is inserted in a recording medium;
With
The second repeating means includes
An internal counter updating means for updating the internal counter when the timing of encryption key update comes;
A second temporary counter updating means for updating the temporary counter when the encryption key update timing comes;
A content recording method comprising: The content recording method according to claim 12, wherein
The temporary counter includes a number of bits corresponding to a count range,
The initialization of the temporary counter is a process of setting the number of bits corresponding to the initialization value to the first value and the remaining bits to the second value,
The updating of the temporary counter is a process of changing one bit from a first value to a second value. The content recording method according to claim 13, wherein
The number of bits corresponding to the count range of the temporary counter corresponds to a range smaller than the entire range of the content,
An offset counter is provided to compensate for the shortage of the number of bits of the temporary counter,
An offset processing unit that operates next to each of the temporary counter updating unit and the second temporary counter updating unit;
The offset processing means is
A content recording method comprising: initializing the temporary counter and changing a count stored in an encryption key seed storage unit. The content recording method according to claim 12, wherein
If there is a temporary counter at the start of the recording,
An internal count value setting means for setting the count value of the temporary counter as an internal count value;
The content recording method, wherein the encryption key generation means operates after the operation of the internal count setting means. The content recording method according to claim 15, wherein
The number of bits corresponding to the count range of the temporary counter corresponds to a range smaller than the entire range of the content,
An offset counter is provided to compensate for the shortage of the number of bits of the temporary counter,
In the internal count value setting means which uses the count value of the temporary counter as an internal count value, the value of the offset counter is further added to the internal counter value. Temporary counter generating means for generating a temporary counter at the start of recording;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking content up to the initialization position of the temporary counter;
Means for generating an encryption seed;
Encryption seed storage means for storing the encryption seed in an encryption key seed storage unit;
An internal counter initialization means for initializing the internal counter;
Encryption key initializing means for generating an encryption key based on the encryption seed and the internal counter of the initial value;
First repeating means for repeating the recording of the content from the initialization position;
A second repeating means for repeating the processing of the counters;
Temporary counter deleting means for deleting the temporary counter operating after the operation of the second repeating means;
With
The first repeating means includes
Means for setting a value of an elapsed counter indicating the elapsed time of the content in the internal counter when the timing of encryption key update comes;
Means for setting the remainder of dividing the internal counter by the number of bits of the temporary counter as the temporary count value when the timing of encryption key update comes;
When the encryption key update timing comes, further, a means obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and multiplying it by the number of bits of the temporary counter is used as an offset value;
Encryption key generation means for generating a new encryption key based on the encryption seed and the updated internal counter when the timing of encryption key update comes,
Content encryption means for encrypting content with the current encryption key;
Internal counter insertion means for inserting the value of the internal counter into the encrypted content;
Content storage means for storing the encrypted content into which the internal counter is inserted in a recording medium;
With
The second repeating means includes
Means for setting a value of an elapsed counter indicating the elapsed time of the content in the internal counter when the timing of encryption key update comes;
Means for setting the remainder of dividing the internal counter by the number of bits of the temporary counter as the temporary count value when the timing of encryption key update comes;
When the encryption key update timing comes, further, a means obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and multiplying it by the number of bits of the temporary counter is used as an offset value;
A content recording method comprising: The content recording method according to claim 17, wherein
The temporary counter includes a number of bits corresponding to a count range,
The initialization of the temporary counter is a process of setting the number of bits corresponding to the initialization value to the first value and the remaining bits to the second value,
The updating of the temporary counter is a process of changing one bit from a first value to a second value. The content recording method according to claim 17, wherein
If there is a temporary counter at the start of the recording,
Means for setting a value of an elapsed counter indicating the elapsed time of the content in the internal counter when the timing of encryption key update comes;
Means for setting the remainder of dividing the internal counter by the number of bits of the temporary counter as the temporary count value when the timing of encryption key update comes;
When the encryption key update timing comes, further, a means obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and multiplying it by the number of bits of the temporary counter is used as an offset value;
Further comprising
A content recording method, wherein the encryption key generating means operates after the operations of these means. It exists in a period that starts when content recording starts and ends when a predetermined time elapses after the content recording ends. In this period, a temporary counter indicating the elapsed time from the start of the content is actually The content playback means operates only when it exists in
The content reproduction means includes
Temporary count reading means for reading the count value of the temporary counter;
Internal count value setting means for setting the read temporary count value as an internal count value;
If the count value inserted at the current position of the content is less than a value obtained by subtracting the internal count value from the count corresponding to the time shift allowable time, the count value inserted at the current position of the content is Seek means for seeking the content until a value obtained by subtracting a count corresponding to the time shift allowable time from the count value;
Count reading means for reading the count value from the current position of the content;
Content output means for performing decryption of the content using the count value and outputting the decrypted content;
A content reproduction method comprising: The content reproduction method according to claim 20,
The temporary counter alone cannot handle the entire range of the content,
In the internal count value setting means, a value obtained by adding an offset value corresponding to the number of times the internal count value is used to the read temporary count value is used as the internal count value. Content playback method. An encryption key generating means for generating an encryption key that changes every predetermined period of content;
An encryption means for encrypting a portion of each predetermined period of the content with an encryption key corresponding to the portion;
Parameter insertion means for inserting a parameter corresponding to an encryption key for each predetermined period of the content into a part of the content for the predetermined period;
Content recording means for recording the content encrypted by the encryption means and having the parameter inserted by the parameter insertion means on a recording medium;
A content recording apparatus comprising: Temporary counter generation means for generating a temporary counter at the start of content movement;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking the content up to the initialization position of the temporary counter;
And repeating means for repeating the movement of the content from the initialization position,
The repeating means includes
Parameter reading means for reading parameters from the content;
If the parameter read in the current iteration is different from the parameter read in the previous iteration, the temporary counter is updated to the value corresponding to the parameter read in the current iteration, and the correspondence of the content Updating means for performing processing for enabling reproduction of the predetermined unit portion to be performed;
Means for reading out a predetermined unit portion of the content, decrypting the predetermined unit portion with an encryption key generated using the parameter,
A content moving apparatus comprising: Temporary counter generating means for generating a temporary counter at the start of content reproduction;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking the content up to a position after the initialization position of the temporary counter;
Repetitive means for repeating reproduction of the content from a position after seek;
With
The repeating means includes
Parameter reading means for reading parameters from the content;
Means for reading a predetermined unit portion of the content, decrypting the predetermined unit portion with an encryption key generated using the parameters, and outputting the decrypted unit portion;
A content playback apparatus comprising: Temporary counter generating means for generating a temporary counter at the start of recording of content;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking content up to the initialization position of the temporary counter;
Means for generating an encryption seed;
Encryption seed storage means for storing the encryption seed in a storage unit;
An internal counter initialization means for initializing the internal counter;
Encryption key initializing means for generating an encryption key based on the encryption seed and the internal counter of the initial value;
First repeating means for repeating the recording of the content from the initialization position;
A second repeating means for repeating the processing of the counters;
Temporary counter deleting means for deleting the temporary counter operating after the operation of the second repeating means;
With
The first repeating means includes
An internal counter updating means for updating the internal counter when the timing of encryption key update comes;
Encryption key generation means for generating a new encryption key based on the encryption seed and the updated internal counter when the timing of encryption key update comes,
A temporary counter update means for updating the temporary counter when an encryption key update timing comes;
Content encryption means for encrypting content with the current encryption key;
Internal counter insertion means for inserting the value of the internal counter into the encrypted content;
Content storage means for storing the encrypted content into which the internal counter is inserted in a recording medium;
With
The second repeating means includes
An internal counter updating means for updating the internal counter when the timing of encryption key update comes;
A second temporary counter updating means for updating the temporary counter when the encryption key update timing comes;
A content recording apparatus comprising: Temporary counter generating means for generating a temporary counter at the start of recording;
Temporary counter initialization means for initializing the temporary counter;
Content seek means for seeking content up to the initialization position of the temporary counter;
Means for generating an encryption seed;
Encryption seed storage means for storing the encryption seed in an encryption key seed storage unit;
An internal counter initialization means for initializing the internal counter;
Encryption key initializing means for generating an encryption key based on the encryption seed and the internal counter of the initial value;
First repeating means for repeating the recording of the content from the initialization position;
A second repeating means for repeating the processing of the counters;
Temporary counter deleting means for deleting the temporary counter operating after the operation of the second repeating means;
With
The first repeating means includes
Means for setting a value of an elapsed counter indicating the elapsed time of the content in the internal counter when the timing of encryption key update comes;
Means for setting the remainder of dividing the internal counter by the number of bits of the temporary counter as the temporary count value when the timing of encryption key update comes;
When the encryption key update timing comes, further, a means obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and multiplying it by the number of bits of the temporary counter is used as an offset value;
Encryption key generation means for generating a new encryption key based on the encryption seed and the updated internal counter when the timing of encryption key update comes,
Content encryption means for encrypting content with the current encryption key;
Internal counter insertion means for inserting the value of the internal counter into the encrypted content;
Content storage means for storing the encrypted content into which the internal counter is inserted in a recording medium;
With
The second repeating means includes
Means for setting a value of an elapsed counter indicating the elapsed time of the content in the internal counter when the timing of encryption key update comes;
Means for setting the remainder of dividing the internal counter by the number of bits of the temporary counter as the temporary count value when the timing of encryption key update comes;
When the encryption key update timing comes, further, a means obtained by multiplying the integer value obtained by dividing the internal counter by the number of bits of the temporary counter and multiplying it by the number of bits of the temporary counter is used as an offset value;
A content recording apparatus comprising: It exists in a period that starts when content recording starts and ends when a predetermined time elapses after the content recording ends. In this period, a temporary counter indicating the elapsed time from the start of the content is actually The content playback means operates only when it exists in
The content reproduction means includes
Temporary count reading means for reading the count value of the temporary counter;
Internal count value setting means for setting the read temporary count value as an internal count value;
If the count value inserted at the current position of the content is less than a value obtained by subtracting the internal count value from the count corresponding to the time shift allowable time, the count value inserted at the current position of the content is Seek means for seeking the content until a value obtained by subtracting a count corresponding to the time shift allowable time from the count value;
Count reading means for reading the count value from the current position of the content;
Content output means for performing decryption of the content using the count value and outputting the decrypted content;
A content playback apparatus comprising:   Once the recorded content is transferred, the cumulative number of bits changed from the first value to the second value is changed according to the amount from the start point of the content to the current transfer location, and A copy-once content control method characterized by prohibiting reproduction and re-transfer of a portion before a portion corresponding to the cumulative number. The copy once content control method according to claim 28,
The bit is stored in a non-volatile memory, and even after the transfer is interrupted, by reading the bit from the non-volatile memory, the accumulated number of changed bits can be grasped, thereby A copy-once content control method, characterized in that the reproduction and transfer of a portion before the portion corresponding to the cumulative number of bits can be prohibited.   Once the content is recorded, the cumulative number of bits changed from the first value to the second value is changed according to the amount from the start point of the content to the current recording location, and the cumulative number of bits is changed. A method of time-shift reproduction of copy never content, wherein reproduction of a portion before a predetermined time from a corresponding portion is prohibited. The time-shift playback method for copy never content according to claim 30,
A method of time-shift reproduction of copy never content, wherein the bit is stored in a non-volatile memory.   Once the recorded content is transferred, the cumulative number of bits changed from the first value to the second value is changed according to the amount from the start point of the content to the current transfer location, and A copy-once content control apparatus characterized by prohibiting reproduction and re-transfer of a portion before a portion corresponding to the cumulative number.   Once the content is recorded, the cumulative number of bits changed from the first value to the second value is changed according to the amount from the start point of the content to the current recording location, and the cumulative number of bits is changed. A time-shift reproduction apparatus for copy never content, wherein reproduction of a portion before a predetermined time from a corresponding portion is prohibited.   A program for causing a computer to perform the method according to any one of claims 1 to 21 or any one of claims 28 to 31.

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