JP2012142045A - Device and method for recording and reproducing - Google Patents

Abstract

A recording / reproducing method and a recording / reproducing apparatus capable of ensuring the authenticity of electronic data recorded on one or a plurality of optical discs.
In a recording / reproducing method for ensuring the authenticity of electronic data recorded on an optical disk, address information indicating a boundary between a recorded area and an unrecorded area on the optical disk when the electronic data is recorded on the optical disk. A hash value is calculated for the address information when the electronic data recorded on the optical disc 1 is reproduced, and the calculated hash value and the first step are calculated. And a second step of comparing the calculated hash value.
[Selection] Figure 4

Description

  The present invention relates to a recording / reproducing method and a recording / reproducing apparatus, and is suitable for application to an electronic data management method and an optical disc drive for ensuring the authenticity of electronic data.

  Since electronic data is digital information, it can be easily rewritten and stored, and is usually recorded and stored in a recording medium such as a hard disk, tape, or optical disk. Among recording media, optical discs are particularly suitable for storage applications, and are suitable for storing important electronic data for a long period of time or reproducing them as necessary. Here, when the recorded electronic data is used as evidence, it is important to prove that the electronic data stored on the optical disc is not falsified. Conventionally, various techniques have been developed to verify that electronic data is not falsified, that is, authenticity of electronic data.

  For example, Patent Document 1 discloses a technique related to a secure electronic media management method for ensuring the authenticity of electronic data recorded on an optical disk on which electronic data has already been recorded by another system. ing. Specifically, all electronic data (files) already recorded on the optical disk are read, a hash value of the read file is calculated, and the calculated hash value and file name are used as one hash entry. One hash file is created from one or a plurality of hash entries, and the created hash file is recorded on a security optical disk.

JP 2002-182963 A

  However, the technique of Patent Document 1 cannot ensure the authenticity of electronic data newly recorded on an optical disc (hereinafter referred to as “additional writing”). In other words, there are optical disks that can be rewritten a plurality of times and those that are called write-once (WO: WriteOnce) that can be recorded only once. In the case of a write-once optical disk, already recorded electronic data is erased. Although it cannot be rewritten, it is possible to add electronic data to a free area of the same optical disc. Therefore, when electronic data is additionally recorded on this write-once optical disc, the authenticity of the additionally recorded electronic data cannot be ensured.

  Further, in the technique of Patent Document 1, it is possible to ensure the authenticity of electronic data recorded on one optical disk. For example, when continuous electronic data is recorded on an optical disk called A and an optical disk called B, The authenticity of electronic data recorded on these optical disks cannot be ensured. Therefore, the authenticity of electronic data recorded by a combination of a plurality of optical disks cannot be ensured.

  The present invention has been made in consideration of the above points, and intends to propose a recording / reproducing method and a recording / reproducing apparatus capable of ensuring the authenticity of electronic data recorded on one or a plurality of optical discs. .

  In order to solve this problem, in the present invention, in a recording / reproducing method for ensuring the authenticity of electronic data recorded on an optical disk, when recording electronic data on the optical disk, recorded areas and unrecorded areas on the optical disk are recorded. A first step of calculating a first hash value from address information indicating a boundary between the first address and a second step of calculating a second hash value from the address information when reproducing electronic data recorded on the optical disc. And a third step of comparing the first hash value and the second hash value.

  According to the present invention, in the recording / reproducing method for ensuring the authenticity of the electronic data recorded on the plurality of optical disks, when the electronic data is recorded on the plurality of optical disks, the recorded areas and the unrecorded areas on the plurality of optical disks are recorded. A first step of calculating one hash value for each of the plurality of optical discs from address information indicating a boundary with an area, and further calculating one first hash value from a combination of the calculated hash values for each optical disc; When reproducing the electronic data recorded on the plurality of optical discs, one hash value is calculated for each of the plurality of optical discs from the address information, and one more first combination is calculated from the calculated combination of hash values for each optical disc. A second step of calculating a hash value of 2, the first hash value and the second hash Characterized in that it comprises a third step of comparing and.

  Further, in the present invention, when recording electronic data on the optical disc in the recording / reproducing apparatus for ensuring the authenticity of the electronic data recorded on the optical disc, the boundary between the recorded area and the unrecorded area on the optical disc is indicated. A first hash value calculation unit that calculates a first hash value from address information, and a second hash that calculates a second hash value from the address information when reproducing electronic data recorded on the optical disc A value calculation unit; and a hash value comparison unit that compares the first hash value and the second hash value.

Further, in the present invention, when recording electronic data on the plurality of optical discs in the recording / reproducing apparatus for ensuring the authenticity of the electronic data recorded on the plurality of optical discs, recorded areas and unrecorded areas on the plurality of optical discs A first hash value for calculating one hash value for each of the plurality of optical discs from address information indicating a boundary with an area, and further calculating a first hash value from a combination of the calculated hash values for each optical disc When reproducing the electronic data recorded on the plurality of optical discs and the calculation unit, one hash value is calculated for each of the plurality of optical discs from the address information, and further from the calculated hash value combination for each optical disc A second hash value calculation unit for calculating one second hash value, the first hash value and the previous A hash value comparing unit for comparing the second hash value,
It is characterized by providing.

  According to the present invention, the authenticity of electronic data recorded on one or a plurality of optical disks can be ensured.

It is a functional block diagram which shows schematic structure of the recording / reproducing apparatus in 1st Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 1st Embodiment. It is a conceptual diagram which shows the data structure of a disk management area | region. It is a flowchart which shows the process sequence of the process for ensuring authenticity in 1st Embodiment. It is a sequence diagram which shows the process sequence of the process for authenticity ensuring in 1st Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 2nd Embodiment. It is a flowchart which shows the process sequence of the process for ensuring authenticity in 2nd Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 3rd Embodiment. It is a flowchart which shows the process sequence of the process for authenticity ensuring in 3rd Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 4th Embodiment. It is a flowchart which shows the process sequence of the process for authenticity ensuring in 4th Embodiment. It is a schematic block diagram which shows the recording / reproducing system in 5th Embodiment. It is an external view which shows the magazine in 5th Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 5th Embodiment. It is a flowchart which shows the process sequence of the process for authenticity ensuring in 5th Embodiment. It is a sequence diagram which shows the process sequence of the process for ensuring authenticity in 5th Embodiment. It is a conceptual diagram which shows the data structure of the optical disk in 5th Embodiment. It is a conceptual diagram which shows the data structure of the conventional optical disk.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  Before describing the embodiment of the present invention in detail, first, a conventional process for ensuring authenticity will be described with reference to FIG.

  First, the data structure of the optical disc 1 will be described. In the case of the optical disc 1, an inner circumference management area R1 is provided on the inner circumference side and an outer circumference management area R2 is provided on the outer circumference side. For example, management information and disk information are stored. The “management information” includes, for example, address information (start address, final address, next recordable address, etc.) required when electronic data is recorded on the optical disc 1, and “disc information” includes the optical disc. Identification information (disc ID, etc.) for identifying 1 is included. The management information and disk information will be described later.

  The optical disc 1 has a user data area R3, and electronic data (here, files # 1 to # 3) is stored in the user data area R3. The electronic data includes, for example, image data, music data, document data, design drawing data, and the like.

  Accordingly, in the case of FIG. 18, the predetermined information described above is stored in the inner circumference management area R1 or the outer circumference management area R2 of the optical disc 1, and the electronic data “files # 1 to # 3” is stored in the user data area R3. Is stored, while an “unrecorded area” is present.

  Next, a conventional process for ensuring authenticity will be described. The process for ensuring authenticity is performed by a recording / reproducing apparatus (see FIG. 1) that records and reproduces electronic data on the optical disc 1.

  The recording / reproducing apparatus first records electronic data (files # 1 to # 3 in this case) recorded in the user data area R3 of the optical disc 1 using a hash function that is a one-way function when electronic data is recorded on the optical disc 1. A hash function (here, hash values H1 to H3), which is a calculation result, is calculated for each of them. Next, the recording / reproducing apparatus further performs a calculation by a hash function on the combination of the hash values H1 to H3, and calculates a hash value (here, one hash file H10) as a calculation result. The recording / reproducing apparatus records the calculated one hash file H10 in a specific recording area of the optical disc 1.

  Note that the recording / reproducing apparatus may record the hash file H10 with an electronic signature added thereto. Here, the hash file H10 is recorded on the optical disc 1, but may be recorded in a predetermined memory or the like in the recording / reproducing apparatus, for example.

  Next, when reproducing the electronic data already recorded on the optical disc 1, the recording / reproducing apparatus performs an operation by a hash function on each of the electronic data (files # 1 to # 3) recorded on the optical disc 1, Each hash value (hash values H1 to H3) is calculated. The recording / reproducing apparatus further performs a calculation using a hash function for each calculated combination of hash values, and calculates a hash value (one hash file H10) as a calculation result. Finally, the recording / reproducing apparatus compares the hash file H10 calculated here with the hash file H10 recorded in advance on the optical disc 1 or the like, and detects the presence or absence of tampering. As a result of comparison, if the two hash values match, the electronic data is not falsified, and if they do not match, the electronic data is falsified.

  As described above, the recording / reproducing apparatus can detect whether or not the electronic data already recorded on the optical disc 1 has been tampered with. If an electronic signature is added to the hash file H10, the hash file H10 itself is tampered with. It can be detected whether or not there is.

(1) First Embodiment Next, a method for ensuring authenticity according to the present embodiment will be described. In this embodiment, the presence / absence of falsification of electronic data is detected by using address information (start address, final address, and next recordable address) indicating the boundary between a recorded area and an unrecorded area in the optical disc 1. This is one of the features.

(1-1) Configuration of Recording / Reproducing Device According to this Embodiment First, a schematic configuration of a recording / reproducing device 10A according to this embodiment will be described with reference to FIG. The recording / reproducing apparatus 10A is an apparatus for recording electronic data on the optical disk 1 or an apparatus for reading and reproducing electronic data from the optical disk 1, and includes a pickup 2, a spindle motor 3, a memory 4, a signal processing circuit 5, a control unit 6A, An interface 7 and a nonvolatile memory 8 are provided.

  When recording electronic data on the optical disc 1, the pickup 2 irradiates the optical disc 1 with laser light and records the encoded electronic data on the optical disc 1. The pickup 2 reads electronic data from the optical disc 1 and outputs the read electronic data to the signal processing circuit 5. The pickup 2 can irradiate the optical disk 1 with laser light and determine the boundary between the recorded area and the unrecorded area where electronic data is recorded on the optical disk 1.

  The spindle motor 3 controls the rotation operation of the optical disc 1 when recording electronic data on the optical disc 1 and reading electronic data from the optical disc 1.

  The memory 4 temporarily stores electronic data when recording the electronic data on the optical disc 1. The memory 4 temporarily stores the read electronic data when the electronic data is read from the optical disc 1 and reproduced.

  The signal processing circuit 5 encodes the electronic data when recording the electronic data on the optical disc 1. The signal processing circuit 5 performs decoding processing such as demodulation, error correction, and rearrangement on the read electronic data when the electronic data is read from the optical disc 1 and reproduced.

  The control unit 6A comprehensively controls the operation of each unit of the recording / reproducing apparatus 10A. For example, the control unit 6A controls the focus and tracking of the pickup 2 so that the laser beam from the pickup 2 is focused on the recording film track on the optical disc 1. Further, the control unit 6A records various information necessary for the process for ensuring authenticity according to the present embodiment in the management area of the optical disc 1, and executes the process for ensuring authenticity.

  The interface 7 inputs electronic data output from an external terminal (for example, a host computer) when recording electronic data on the optical disc 1, and outputs the input electronic data to the signal processing circuit 5. The interface 7 outputs the decoded electronic data to the host computer 200 when reading the electronic data from the optical disc 1 and reproducing it.

  The non-volatile memory 8 is a non-volatile memory that can store electronic data even when the entire recording / reproducing apparatus 10A is turned off, and stores electronic data that the recording / reproducing apparatus 10A wants to hold. Although the nonvolatile memory 8 is connected to the control unit 6A here, it is not necessarily limited to this. For example, the nonvolatile memory 8 may be connected to the signal processing circuit 5 or may be configured as a part of the memory 4.

(1-2) Data Configuration of Optical Disc in the Present Embodiment Next, a data configuration recorded on the optical disc 1 in the present embodiment will be described with reference to FIG.

  The optical disc 1 is a write-once type optical disc, and includes an inner circumference management area R1 and an outer circumference management area R2. Address information is stored in the inner circumference management area R1 or the outer circumference management area R2.

  Here, the “address information” is information indicating the boundary between the recorded area and the unrecorded area, and the recording start position of the electronic data recording start position or the start position of the electronic data recording is completed. A “final address” indicating the recorded position and a “next recordable address” indicating the position of the additional recording start when the electronic data is additionally recorded are included.

  As shown in FIG. 2, the optical disc 1 is configured to have a user data area R3, and electronic data is stored in each area (area # 1 to # 3) of the user data area R3.

  Therefore, in the case of FIG. 2, the address information is stored in the inner circumference management area R1 or the outer circumference management area R2 of the optical disc 1, and the area # 1 and the area # 2 of the user data area R3 are respectively up to the middle of the area. The electronic data has already been recorded, and it is indicated that the electronic data is not yet stored in the area # 3.

  Next, with reference to FIG. 3, the address information and other various information stored in the inner circumference management area R1 or the outer circumference management area R2 will be described. FIG. 3 shows the data structure of the inner circumference management area R1 in the inner circumference management area R1 or the outer circumference management area R2. As is clear from FIG. 3, the inner circumference management area R1 is composed of a management information area R11, a trial writing (hereinafter referred to as OPC; Optimum Power Control) area R12, a recording time area R13, and a disc information area R14. .

  In the management information area R11, as described above, address information indicating the boundary between the recorded area and the unrecorded area in each area (areas # 1 to # 3) is stored. In addition, the address information includes a start address indicating a position at which electronic data recording is started or started, a final address indicating a position at which recording of electronic data is ended, and a next recording indicating a position at which additional recording is started when electronic data is additionally recorded. Contains possible addresses.

  Here, in the case of the write-once type optical disc 1, so-called overwriting such as erasing electronic data already stored on the optical disc 1 and newly recording electronic data in the same area as the erased area cannot be performed. That is, in the case of the write-once type optical disc 1, overwriting is not possible even if additional writing is possible. Therefore, when adding electronic data to the write-once optical disc 1 in which electronic data has already been recorded, the electronic data is added to the unrecorded area, and the electronic data is recorded from the next recordable address. become. Therefore, if there is a postscript, the address information managed in advance is changed, and by managing the address information, it is possible to easily detect the presence or absence of falsification of the electronic data.

  The OPC area R12 is an area used for trial writing before the electronic data is actually recorded in the user data area (areas # 1 to # 3) of the optical disc 1, and has the power for recording the electronic data. It is used to make adjustments and is added each time you record. The OPC area R12 stores information indicating how far the OPC area R12 has been used. Specifically, a “next trial writing start address (hereinafter referred to as a next OPC start address)” indicating the position of the additional writing start when electronic data is additionally written is stored.

  Further, recording time information when the electronic data is recorded on the optical disc 1 is stored in the recording time region R13. Here, the recording time area R13 is provided in the inner circumference management area R1, and the recording time information is stored in the recording time area R13. However, the present invention is not limited to this. For example, the recording time information is stored in the management information area R11. It may be stored.

  The disc information area R14 stores identification information unique to the optical disc 1, for example, the disc ID of the optical disc 1.

  Further, the spare areas R15 and R16 store various other information necessary for managing the optical disc 1.

(1-3) Process for Securing Authenticity According to the Present Embodiment Next, with reference to FIG. 4, a processing procedure for process for ensuring authenticity according to the present embodiment will be described. The following process for ensuring authenticity is executed by the control unit 6A of the recording / reproducing apparatus 10A that has received an instruction from the host computer 200. When the control unit 6A of the recording / reproducing apparatus 10A receives an instruction to reproduce the optical disc 1 from the host computer 200, the control unit 6A starts processing for ensuring authenticity shown in FIG.

  Here, before describing the process for ensuring authenticity shown in FIG. 4, the preprocess for the process for ensuring authenticity by the control unit 6A of the recording / reproducing apparatus 10A will be described.

  When the electronic data is recorded on the new optical disk 1, the control unit 6A, for example, when the optical disk 1 is ejected, the address information of each area # 1 to # 3 is stored in the management information area R11 of the management area (R1 or R2). Record it. The address information here refers to the above-described “start address”, “last address”, and “next recordable address”.

  Then, the control unit 6A uses a hash function that is a one-way function for the “final address” (“start address” for the region # 3) among the address information of the regions # 1 to # 3 recorded in the management region. A hash function is calculated for the final address of each area ("start address" for area # 3), and a hash value as a calculation result is calculated. Here, three hash values for the final addresses or start addresses of the areas # 1 to # 3 are calculated. Then, the control unit 6A records the calculated three hash values in a specific area of the optical disc 1.

  Through the pre-processing described above, the address information indicating the boundary between the recorded area and the unrecorded area and the hash value for this address information are recorded in advance on the optical disc 1.

  Next, processing for ensuring authenticity shown in FIG. 4 will be described. First, when reproducing the electronic data recorded on the optical disc 1, the controller 6A reads the address information stored in the management area (R1 or R2) of the optical disc 1 (S1), and then the controller 6A It is determined whether or not the address information of all areas (areas # 1 to # 3) has been read (S2).

  Note that the “last address” is assumed as the address information read here, but is not limited to this, and is an address indicating the boundary between the recorded area and the unrecorded area in each area (area # 1 to # 3). For example, it may be a “next recordable address”. In addition, since there is no recorded area for the area # 3 and the entire area is an unrecorded area, the address indicating the boundary between the recorded area and the unrecorded area is the “start address”.

  If the control unit 6A obtains a negative result in this determination, it proceeds to step S1 and reads the address information of another area that has not been read yet. The controller 6A repeats the processes of steps S1 and S2 until the address information of all areas (areas # 1 to # 3) of the optical disc 1 is read.

  On the other hand, when the control unit 6A obtains a positive result in the determination at step S2, the control unit 6A then uses the hash function which is a one-way function to perform the address information on each read area (areas # 1 to # 3). Then, a hash function is calculated, and a hash value as a calculation result is calculated for each region (S3).

  On the other hand, the control unit 6A reads the hash value for the address information of each area recorded in advance on the optical disc 1 from the optical disc 1 (S4), and compares the read hash value with the hash value calculated in step S3. It is then determined whether or not both hash values match (S5).

  If the control unit 6A obtains a positive result in this determination, it determines that both hash values match and the electronic data of the optical disc 1 to be reproduced has not been tampered with, and ends this process. On the other hand, if the control unit 6A obtains a negative result in the determination at step S5, the control unit 6A determines that the two hash values do not match and the electronic data of the optical disc 1 to be reproduced has been falsified. Therefore, the control unit 6A adds a mismatch flag to the response command output to the host computer 200 (S6), and ends this process.

  Next, FIG. 5 shows the relationship between the host computer 200 performed when reproducing the optical disc 1 and the control unit 6A of the recording / reproducing apparatus 10A in relation to the above-described process for ensuring authenticity according to the present embodiment. The exchange of signals is shown. The host computer 200 outputs a playback instruction for the optical disc 1 to the recording / reproducing apparatus 10A, and this processing is started.

  First, the host computer 200 outputs a command (hereinafter referred to as an address confirmation command) requesting confirmation of the final address of the area # 1 in the optical disc 1 to the recording / reproducing apparatus 10A together with a reproduction instruction (S11). In response to this, the control unit 6A acquires the final address of the area # 1 from the management area (R1 or R2) of the optical disc 1, and sends a command (hereinafter referred to as an address response command) to notify the acquisition to the host computer. 200 (S12).

  The host computer 200 and the control unit 6A perform the same exchanges as in steps S11 and S12 described above for the other areas (areas # 2 and # 3) of the optical disc 1 (S13 to S16). When the exchange of the address confirmation command and the address response command is completed for the entire area, the host computer 200 requests the control unit 6A to read the hash value recorded on the optical disc 1 (hereinafter referred to as a hash value read command). Output) (S17).

  In response to this, the control unit 6A reads a hash value recorded in a specific area of the optical disc 1, and sends a command notifying that the hash value has been read (hereinafter referred to as a hash value response command) to the host computer. 200 (S18).

  Through the above exchange, the control unit 6A can acquire the final addresses of all the areas (areas # 1 to # 3) of the optical disc 1 and the hash value recorded in advance on the optical disc 1, and the acquired final value. Based on the address and the hash value, it is possible to detect whether or not the electronic data has been tampered with by performing the above-described process for ensuring authenticity in FIG.

  In FIG. 5, the control unit 6A outputs an address response command and a hash value response command to the host computer 200. However, the present invention is not limited to this, and the control unit 6A sends regions # 1 to # 3 to the host computer 200. It is also possible to output the final address of all the areas and the hash value recorded in advance on the optical disc 1. In this case, the host computer 200 that has acquired the final address and the hash value can detect whether the electronic data has been tampered with.

  As a modification, in the above-described process for ensuring authenticity (see FIG. 4), the control unit 6A reads a hash value from the optical disc 1 (see FIG. 4: S4). 6A records the hash value in the non-volatile memory 8 of the recording / reproducing apparatus 10A at the pre-processing stage of the process for ensuring authenticity, and the hash value is stored from the non-volatile memory 8 in the process for ensuring authenticity. It may be read.

  When the recording / reproducing apparatus 10A is connected to a network (not shown), the control unit 6A records the hash value in a database on the network at the pre-processing stage for ensuring authenticity, and authenticates the authenticity. In the process for ensuring the security, the address information may be read from a database on the network.

  In the above-described process for ensuring authenticity, the control unit 6A calculates a hash value for address information using a hash function as an example of a one-way function (see FIG. 4: S3). The controller 6A records the address information itself in, for example, the non-volatile memory 8 or the database other than the optical disk 1 at the stage of pre-processing for ensuring authenticity, and the optical disk 1 in the process for ensuring authenticity. It is also possible to compare the address information read from the address information read from the nonvolatile memory 8 or the like.

  In addition, a specific value is calculated from the address information by using some other encryption method other than the hash value, and the control unit 6A compares the specific value in the process for ensuring authenticity. Also good.

  Some optical disks have individual disk IDs such as serial numbers attached one by one. Therefore, the hash value for the disk ID and the hash value for the address information are combined to calculate one more hash value, and the control unit 6A compares this hash value in the process for ensuring authenticity. It is good.

  Further, the control unit 6A may further calculate one hash value by combining the hash file in the prior art and the hash value for the address information, and compare this hash value in the process for ensuring authenticity. Good.

  Note that the timing at which the address information is recorded in the management area (R1 or R2) is, for example, when the optical disc 1 is ejected or finalized. In the finalizing process, since termination processing is performed on the optical disc 1, electronic data is not normally added to the optical disc 1 thereafter. Therefore, the timing for recording the address information in the management area (R1 or R2) may be after the finalizing process. When the optical disc 1 is ejected before the finalizing process, the address information is recorded as temporary address information in a temporary management area (for example, the spare area R15 or R16). When the optical disk 1 is ejected in this state, the address information may be recorded separately as being recorded in the formal management area (for example, the management information area R11) as the formal address information.

(1-4) Effects of the Present Embodiment As described above, according to the present embodiment, recording is performed on the write-once optical disc 1 using the address information indicating the boundary between the recorded area and the unrecorded area. The presence or absence of falsification of the electronic data can be detected, and the authenticity of the electronic data can be ensured. Further, by using the disk ID and the hash value for the prior art file together with the address information, it is possible to more reliably detect the presence or absence of falsification of the electronic data.

(2) Second Embodiment (2-1) Configuration of Recording / Reproducing Device According to This Embodiment and Data Configuration of Optical Disc According to This Embodiment In FIG. 1, 10B is a recording according to the second embodiment as a whole. A playback device 10B is shown. This recording / reproducing apparatus 10B uses the address information (next OPC start address) indicating the boundary between the already recorded area and the unrecorded area as the OPC area R12 in the management area (R1 or R2). The recording / reproducing apparatus 10A according to the first embodiment is configured in the same manner. The recording / reproducing apparatus 10B according to the present embodiment uses the address information (next OPC start address) indicating the boundary between the recorded area and the unrecorded area as the OPC area in the optical disc 1 to alter the electronic data. One of the features is that the presence or absence can be detected.

  FIG. 6 shows the data structure of the optical disc 1 according to this embodiment, and the inner circumference management area R1 and the outer circumference management area R2 include an OPC area R12. Note that the OPC area R12 is an area used for test writing to adjust the recording power as described in FIG. 3 above. When the electronic data is recorded on the optical disc 1 by performing the OPC adjustment, This area is added each time electronic data is recorded. The OPC area R12 stores address information indicating the boundary between the recorded area and the unrecorded area as the OPC area R12. The address information here includes, for example, a “next OPC start address” indicating the position of the start of additional writing when electronic data is additionally written.

  Accordingly, in the case of FIG. 6, the inner circumference management area R1 or the outer circumference management area R2 of the optical disc 1 includes the OPC area R12, and the “next OPC start address” is stored in the OPC area R12. In addition, in the area # 1 and the area # 2 of the user data area R3, the electronic data has already been recorded to the middle of the area, and the electronic data has not yet been stored in the area # 3. It is shown.

(2-2) Processing for Securing Authenticity According to Second Embodiment Next, a processing procedure for processing for ensuring authenticity according to the present embodiment will be described with reference to FIG. The following processing for ensuring authenticity is executed by the control unit 6B of the recording / reproducing apparatus 10B that has received an instruction from the host computer 200. When the control unit 6B of the recording / reproducing apparatus 10B receives an instruction to reproduce the optical disc 1 from the host computer 200, the control unit 6B starts processing for ensuring authenticity shown in FIG.

  Before describing the process for ensuring authenticity shown in FIG. 7, the preprocess for the process for ensuring authenticity by the control unit 6B of the recording / reproducing apparatus 10B will be described.

  After the electronic data is recorded on the new optical disc 1, the control unit 6B, for example, when the optical disc 1 is ejected, the recorded area as the OPC area R12 and the unrecorded area in the OPC area R12 of the management area (R1 or R2) Address information indicating the boundary of the address is recorded. Note that the address information here refers to the “next OPC start address” described above, and the control unit 6B performs the OPC adjustment to add the electronic data to the optical disc 1 from the next OPC start address to the OPC area. Will be added.

  Then, the control unit 6B performs a calculation using the hash function on the next OPC start address using the hash function that is a one-way function for the “next OPC start address” recorded in the management area (R1 or R2), and the calculation result A hash value is calculated. Then, the control unit 6B records the calculated hash value in a specific area of the optical disc 1.

  As a result of the pre-processing described above, the address information indicating the boundary between the recorded area and the unrecorded area as the OPC area and the hash value for this address information are recorded in advance on the optical disc 1.

Next, processing for ensuring authenticity shown in FIG. 7 will be described. First, when reproducing the electronic data recorded on the optical disc 1, the control unit 6B reads the address information stored in the management area (R1 or R2) of the optical disc 1 (S1a), and then the control unit 6B It is determined whether the address information of all areas of the inner circumference management area R1 and the outer circumference management area R2 has been read (S2a).

  The address information to be read here is assumed to be the “next OPC start address”, but is not limited to this. In the management area (R1 or R2), an area that has been recorded as an OPC area and an area that has not been recorded as an OPC area For example, an “OPC final address” indicating the final position of an area recorded as an OPC area may be used.

  If the control unit 6B obtains a negative result in this determination, it proceeds to step S1a and reads the address information in another management area that has not been read yet. The control unit 6B repeats the processes of steps S1a and S2a until address information is read from all areas of the inner circumference management area R1 and the outer circumference management area R2 of the optical disc 1.

  On the other hand, when the control unit 6B obtains a positive result in the determination at step S2a, it uses the hash function that is a one-way function to perform an operation using the hash function on the read address information. A hash value is calculated (S3a).

  Then, the control unit 6B reads the hash value corresponding to the address information recorded in advance on the optical disc 1 from the optical disc 1 (S4a), compares the read hash value with the hash value calculated in step S3a, and stores both hashes. It is determined whether or not the values match (S5a).

  If the control unit 6B obtains a positive result in this determination, it determines that both hash values match and the electronic data of the optical disc 1 to be reproduced has not been tampered with, and ends this process. On the other hand, when the control unit 6B obtains a negative result in the determination at step S5a, the control unit 6B determines that both hash values do not match and the electronic data of the optical disc 1 to be reproduced has been falsified. Therefore, the control unit 6B adds a mismatch flag to the response command output to the host computer 200 (S6a), and ends this process.

(2-3) Effects of this Embodiment As described above, according to this embodiment, write-once is performed using address information indicating the boundary between a recorded area as an OPC area and an unrecorded area as an OPC area. The presence or absence of falsification of electronic data recorded on the optical disc 1 can be detected, and the authenticity of the electronic data can be ensured.

(3) Third embodiment (3-1) Configuration of recording / reproducing apparatus according to this embodiment and data configuration of optical disc according to this embodiment In FIG. 1, 10C is a recording according to the third embodiment as a whole. A playback device 10C is shown. The recording / reproducing apparatus 10C is configured in the same manner as the recording / reproducing apparatus 10A according to the first embodiment except that the recording time information read from the recording time area R13 in the management area (R1 or R2) is used. . One feature of the recording / reproducing apparatus 10C according to the present embodiment is that it can detect the presence / absence of tampering using recording time information in addition to address information.

  FIG. 8 shows the data structure of the optical disc 1 according to the present embodiment, and the inner management area R1 or the outer management area R2 includes a management information area R11 and a recording time area R13. As described with reference to FIG. 3, the management information area R11 stores address information indicating the boundary between the recorded area and the unrecorded area. The recording time area R13 records electronic data on the optical disc 1. The recording time information at the time of the recording is stored.

  By the way, when recording the electronic data on the optical disc 1, the recording / reproducing apparatus 10C records the recording time information at the time of recording in a specific area of the optical disc 1 with the electronic time being added to the electronic data. Since it is one of various types of information added to the recording time, it is necessary to analyze and detect it by a predetermined special method when recording time information is to be acquired later. Therefore, in the present embodiment, for example, recording time information when electronic data is recorded is acquired from an external terminal such as the host computer 200 connected to the recording / reproducing apparatus 10, and the acquired recording time information is stored on a specific disk on the optical disc 1. Record in the area. By doing in this way, the effort which analyzes various information added to electronic data can be omitted.

  Therefore, in the case of FIG. 8, the recording time information is stored in the inner circumference management area R1 or the outer circumference management area R2 of the optical disc 1, and the area # 1 and the area # 2 of the user data area R3 are respectively the areas. It is shown that electronic data has already been recorded halfway, and the electronic data is not yet stored in area # 3.

(3-2) Process for Securing Authenticity According to Third Embodiment Next, a processing procedure of a process for ensuring authenticity according to the present embodiment will be described with reference to FIG. The following process for ensuring authenticity is executed by the control unit 6C of the recording / reproducing apparatus 10C that has received an instruction from the host computer 200. When the control unit 6C of the recording / reproducing apparatus 10C receives an instruction to reproduce the optical disc 1 from the host computer 200, the control unit 6C starts processing for ensuring authenticity shown in FIG.

Before describing the process for ensuring authenticity shown in FIG. 9, the preprocess for the process for ensuring authenticity by the control unit 6C of the recording / reproducing apparatus 10C will be described.
After the electronic data is recorded on the new optical disk 1, the control unit 6C, for example, when the optical disk 1 is ejected, the address information of each area # 1 to # 3 is stored in the management information area R11 of the management area (R1 or R2). Record it. The address information here is the “start address”, “last address”, and “next recordable address” described above in the description of the first embodiment, and includes the recorded area and the unrecorded area. This is an address indicating a boundary.

  Further, the control unit 6C acquires the recording time information when the electronic data is recorded on the optical disc 1 from the host computer 200, and records the acquired recording time information in the recording time region R13 of the management region (R1 or R2). .

  The control unit 6C is a one-way function for the “last address” (“start address” for the area # 3) among the address information of the areas # 1 to # 3 recorded in the management area (R1 or R2). A hash function is used to calculate the final address of each area ("start address" for area # 3) using a hash function, and a hash value that is the calculation result is calculated. On the other hand, the control unit 6C calculates a hash value for the recording time information recorded in the management area (R1 or R2). Then, the control unit 6C calculates one more hash value for each calculated combination of hash values, and records the calculated hash value in a specific area of the optical disc 1.

  By the above preprocessing, the optical disc 1 is recorded in advance with address information indicating the boundary between the recorded area and the unrecorded area, recording time information when electronic data is recorded, and hash values for these information. Become.

  Next, processing for ensuring authenticity shown in FIG. 9 will be described. First, when reproducing the electronic data recorded on the optical disc 1, the control unit 6C reads the address information stored in the management area (R1 or R2) of the optical disc 1 (S1b), and then the control unit 6C It is determined whether the address information of all the areas (areas # 1 to # 3) has been read (S2b).

  Note that the “last address” is assumed as address information to be read here, but is not necessarily limited thereto, and an address indicating a boundary between a recorded area and an unrecorded area in each area (area # 1 to # 3). For example, it may be a “next recordable address”. In addition, since there is no recorded area for the area # 3 and the entire area is an unrecorded area, the address indicating the boundary between the recorded area and the unrecorded area is the “start address”.

  If the controller 6C obtains a negative result in this determination, it proceeds to step S1b and reads the address information of another area that has not yet been read. The controller 6C repeats the processes of steps S1b and S2b until the address information of all areas (areas # 1 to # 3) of the optical disc 1 is read.

  On the other hand, if the control unit 6C obtains a positive result in the determination at step S2b, it next reads the recording time information from the recording time region R13 in the management region (R1 or R2) (S3b). Then, the control unit 6C uses a hash function that is a one-way function to perform an operation using the hash function on the address information and recording time information of each read area (areas # 1 to # 3), and the result is an operation result. Each hash value is calculated. Furthermore, the control unit 6C calculates one hash value for each calculated combination of hash values (S4b).

  Then, the control unit 6C reads the hash value for the combination of the hash value for the address information recorded in advance on the optical disc 1 and the hash value for the recording time information from the optical disc 1 (S5b), and the read hash value and step S4b. The calculated hash value is compared to determine whether or not both hash values match (S6b).

  If the control unit 6C obtains a positive result in this determination, it determines that both hash values match and that the electronic data of the optical disc 1 to be reproduced has not been tampered with, and ends this process. On the other hand, if the control unit 6C obtains a negative result in the determination at step S6b, the control unit 6C determines that the two hash values do not match and the electronic data of the optical disc 1 to be reproduced has been falsified. Therefore, the control unit 6C adds a mismatch flag to the response command output to the host computer 200 (S7b), and ends this process.

(3-3) Effects of this Embodiment As described above, according to this embodiment, since the presence / absence of falsification is detected using recording time information in addition to address information, recording according to the first embodiment is performed. Compared with the playback apparatus 10A, it is possible to detect the presence or absence of falsification more accurately, and to ensure the authenticity of electronic data. In the present embodiment, the presence or absence of falsification of electronic data is detected using a hash value for a combination of hash values for address information and recording time information. However, the present invention is not limited to this, and the second embodiment described above. Also, the “next OPC start address” may be used to detect the presence or absence of falsification using the address information, the recording time information, and the next OPC start address. In this case, the presence / absence of falsification can be detected more accurately.

(4) Fourth Embodiment (4-1) Configuration of Recording / Reproducing Device According to This Embodiment and Data Configuration of Optical Disc According to This Embodiment In FIG. 1, 10D is a recording according to the fourth embodiment as a whole. A playback device 10D is shown. The recording / reproducing apparatus 10D is the first embodiment except that the recording time information read from the recording time area R13 in the management area (R1 or R2) and the disc ID read from the disc information area R14 are used in combination. The recording / reproducing apparatus 10D is configured in the same manner. One of the features of the recording / reproducing apparatus 10D according to the present embodiment is that it can detect the presence / absence of tampering using the disk ID in addition to the address information.

  FIG. 10 shows the data configuration of the optical disc 1 according to the present embodiment, and the inner circumference management area R1 or the outer circumference management area R2 includes a management information area R11, a recording time area R13, and a disc information area R14. As described with reference to FIG. 3, the management information area R11 stores address information indicating the boundary between the recorded area and the unrecorded area. The recording time area R13 records electronic data on the optical disc 1. Recording time information at the time of recording is stored, and a disk ID is stored in the disk information area R14.

  Therefore, in the case of FIG. 10, address information, recording time information, and disc ID are stored in the inner circumference management area R1 or outer circumference management area R2 of the optical disc 1, and the area # 1 and area # 2 of the user data area R3. Indicates that electronic data has already been recorded to the middle of each area, and that electronic data has not yet been stored and is not recorded in area # 3.

(4-2) Process for Securing Authenticity According to Fourth Embodiment Next, a processing procedure of a process for ensuring authenticity according to the present embodiment will be described with reference to FIG. The following process for ensuring authenticity is executed by the control unit 6D of the recording / reproducing apparatus 10D that has received an instruction from the host computer 200. When the control unit 6D of the recording / reproducing apparatus 10D receives an instruction to reproduce the optical disc 1 from the host computer 200, the control unit 6D starts processing for ensuring authenticity shown in FIG.

  Before describing the process for ensuring authenticity shown in FIG. 11, the preprocess for the process for ensuring authenticity by the control unit 6D of the recording / reproducing apparatus 10D will be described.

  After the electronic data is recorded on the new optical disc 1, the control unit 6D, for example, when the optical disc 1 is ejected, the address information of each area # 1 to # 3 is stored in the management information area R11 of the management area (R1 or R2). Record it. The address information here is the “start address”, “last address”, and “next recordable address” described above in the description of the first embodiment, and includes the recorded area and the unrecorded area. This is an address indicating a boundary.

  Further, the control unit 6D acquires the recording time information when the electronic data is recorded on the optical disc 1 from the host computer 200, and records the acquired recording time information in the recording time area R13 of the management area (R1 or R2). .

  Further, the control unit 6D records the disc ID of the optical disc 1 in the disc information area R14. The disc ID may be recorded in advance in a specific recording area of the optical disc 1.

  The control unit 6D is a one-way function for the “last address” (“start address” for the area # 3) among the address information of the areas # 1 to # 3 recorded in the management area (R1 or R2). A hash function is used to calculate the final address of each area ("start address" for area # 3) using a hash function, and a hash value that is the calculation result is calculated. On the other hand, the control unit 6D calculates a hash value for the recording time information recorded in the management area (R1 or R2). In addition, the control unit 6D calculates a hash value for the disk ID recorded in the management area (R1 or R2).

Then, the control unit 6D further calculates one hash value for each calculated combination of hash values, and records the calculated hash value in a specific area of the optical disc 1.
As a result of the pre-processing described above, the optical disk 1 is recorded in advance with address information indicating the boundary between the recorded area and the unrecorded area, recording time information when electronic data is recorded, a disk ID, and a hash value for these information. Will be.

  Next, processing for ensuring authenticity shown in FIG. 11 will be described. First, when reproducing the electronic data recorded on the optical disc 1, the control unit 6D reads the address information stored in the management area (R1 or R2) of the optical disc 1 (S1c), and then the control unit 6D It is determined whether the address information of all the areas (areas # 1 to # 3) has been read (S2c).

  Note that the “last address” is assumed as address information to be read here, but is not necessarily limited thereto, and an address indicating a boundary between a recorded area and an unrecorded area in each area (area # 1 to # 3). For example, it may be a “next recordable address”. In addition, since there is no recorded area for the area # 3 and the entire area is an unrecorded area, the address indicating the boundary between the recorded area and the unrecorded area is the “start address”.

  If the control unit 6D obtains a negative result in this determination, the control unit 6D proceeds to step S1c and reads the address information of another area that has not been read yet. The controller 6D repeats the processes of steps S1c and S2c until the address information of all areas (areas # 1 to # 3) of the optical disc 1 is read.

  On the other hand, when the control unit 6D obtains a positive result in the determination at step S2c, it next reads the recording time information from the recording time area R13 in the management area (R1 or R2), and the disk ID from the disk information area R14. Read (S3c). Then, the control unit 6D uses a hash function that is a one-way function to perform an operation using the hash function on the address information, recording time information, and disc ID of each read area (areas # 1 to # 3). A hash value as a result is calculated. Furthermore, the control unit 6D calculates one hash value for each calculated combination of hash values (S4c).

  Then, the control unit 6D reads the hash value for the combination of the hash value for the address information recorded in advance on the optical disc 1, the hash value for the recording time information, and the hash value for the disc ID from the optical disc 1 (S5c). The value is compared with the hash value calculated in step S4c to determine whether or not both hash values match (S6c).

  If the control unit 6D obtains a positive result in this determination, it determines that both hash values match and the electronic data of the optical disc 1 to be reproduced has not been tampered with, and ends this process. On the other hand, when the control unit 6D obtains a negative result in the determination at step S6c, the control unit 6D determines that the two hash values do not match and the electronic data of the optical disc 1 to be reproduced has been falsified. Therefore, the control unit 6D adds a mismatch flag to the response command output to the host computer 200 (S7c), and ends this process.

(4-3) Effects of this Embodiment As described above, according to this embodiment, since the presence or absence of tampering is detected using the disk ID in addition to the address information, recording according to the first embodiment is performed. Compared with the playback apparatus 10A, it is possible to detect the presence or absence of falsification more accurately, and to ensure the authenticity of electronic data.

(5) Fifth Embodiment In the present embodiment, electronic data recorded on a plurality of optical disks 1 using one disk hash value for each of a plurality of optical disks 1 and one magazine hash value based on a combination thereof. One of the features is that the presence or absence of tampering can be detected.

(5-1) Configuration of Recording / Reproducing System According to this Embodiment FIG. 12 is a schematic configuration diagram of the recording / reproducing system 100 according to this embodiment. The recording / reproducing system 100 is a system for recording electronic data on a plurality of optical discs 1 or a system for reading and reproducing electronic data from a plurality of optical discs 1, and a changer control device 101 and a plurality of (here, four) recording units. The playback apparatus 10A is configured to be connected to the host computer 200 via the network N.

  The changer control device 101 includes a network interface 102, a control unit 103, a storage circuit 104, a drive interface 105, and an RF-ID (Radio Frequency IDentification) tag reader / writer 106.

  When recording the electronic data on the optical disc 1, the network interface 102 receives a status confirmation command from the host computer 200 and outputs the received status confirmation command to the control unit 103.

  The control unit 103 comprehensively controls the operation of each unit of the changer control device 101. For example, when recording the electronic data on the optical disc 1, the control unit 103 receives and analyzes the status confirmation command transmitted from the host computer 200 via the network interface 102 and also confirms the status via the drive interface 105. The command is output to a plurality of recording / reproducing devices 10A.

  When the control unit 103 receives a status command indicating whether or not recording is possible from the plurality of recording / reproducing apparatuses 10 </ b> A, the control unit 103 transmits the status command to the host computer 200 via the network interface 102. The control unit 103 records the electronic data on the optical disc 1 by the plurality of recording / reproducing devices 10A, and then transmits a recording end command from the plurality of recording / reproducing devices 10A to the host computer 200.

  Note that the exchange of commands as described above is not performed only when electronic data is recorded on the optical disc 1 but is always performed when the host computer 200 confirms the state of the recording / reproducing system 100. In addition, the host computer 200 does not recognize the plurality of recording / reproducing devices 10A, but recognizes it as one recording device including the large-capacity optical disk 1.

  The storage circuit 104 temporarily stores electronic data transmitted from the host computer 200. Further, the drive interface 105 outputs a status confirmation command from the control unit 103 to the plurality of recording / reproducing devices 10A, and outputs a status command and a recording end command from the plurality of recording / reproducing devices 10A to the control unit 103.

  The RF-ID tag reader / writer 106 reads various information recorded on the RF-ID tag 107a attached to the magazine 107, or records various information on the RF-ID tag 107a. For example, the reader / writer for RF-ID tag 106 reads information relating to a combination of disk IDs of a plurality of optical discs 1 in the magazine 107 recorded in the RF-ID tag 107 a, information relating to the read disc ID, and the magazine 107. The information about the combination of the disk IDs read from the plurality of optical disks 1 actually stored therein is collated, and if the result of the collation is not the same, the fact is notified to the user.

  FIG. 13 shows an external view of a magazine 107 that accommodates a plurality of optical disks 1. The magazine 107 includes an RF-ID tag 107a, and the RF-ID tag 107a includes a memory capable of storing various information.

  As described above, the electronic data is distributed and recorded on the plurality of optical discs 1 so that the apparent recording speed can be increased. If even one of the plurality of optical disks 1 is missing, it is impossible to restore the continuously recorded electronic data. Therefore, a method of recording such continuous electronic data on a plurality of optical discs 1 is useful because it leads to security enhancement with respect to a removable recording medium.

(5-2) Data Configuration of Optical Disc According to Fifth Embodiment Next, a data configuration of a plurality of optical discs 1 according to this embodiment will be described. In the present embodiment, address information (start address, final address and next recordable address) indicating boundaries between recorded areas and unrecorded areas in each of the plurality of optical disks 1 (1-1 to 1-4), and a plurality of One of the features is that the presence or absence of falsification of electronic data can be detected by using the disk ID of the optical disk 1 (1-1 to 1-4).

  FIG. 14 shows the data structure of each of the plurality of optical discs 1 and shows that address information is stored in each of the plurality of optical discs 1. Further, for each optical disc 1, one hash value further calculated by combining hash values calculated for the address information is stored. Therefore, here, since four optical disks 1 are taken as an example, four hash values are stored in each optical disk 1.

(5-3) Process for Securing Authenticity According to Fifth Embodiment Next, with reference to FIG. 15, a processing procedure for process for ensuring authenticity according to the present embodiment will be described. The following process for ensuring authenticity is executed by the control unit 103 of the changer control apparatus 101 that has received an instruction from the host computer 200. When the control unit 103 of the changer control apparatus 101 receives a reproduction instruction for a plurality of optical disks 1 from the host computer 200, the control unit 103 starts a process for ensuring authenticity shown in FIG.

  Before describing the process for ensuring authenticity shown in FIG. 15, the process for preserving authenticity by the control unit 103 of the changer control apparatus 101 will be described.

  After the electronic data is recorded on the plurality of new optical disks 1, the control unit 103, for example, in each of the areas # 1 to # 3 in the management information area R11 of the management area (R1 or R2) when ejecting the plurality of optical disks 1 Record the address information. Note that the address information here is the above-described “start address”, “last address”, and “next recordable address”.

  The control unit 103 is a one-way function for the “last address” (“start address” for the area # 3) among the address information of the areas # 1 to # 3 recorded in the management area (R1 or R2). A hash function is used to calculate the final address of each area ("start address" for area # 3) using a hash function, and a hash value that is the calculation result is calculated. Here, for one optical disk 1, three hash values for the final addresses or start addresses of the areas # 1 to # 3 are calculated. Further, the control unit 103 further calculates one hash value (hereinafter referred to as a disk hash value) for the combination of the three hash values from the calculated three hash values, and uses the calculated disk hash value for the optical disc 1. Record in a specific area. The control unit 103 performs this for each of the plurality of optical disks 1, calculates one disk hash value for each of the plurality of optical disks 1, and records it in each specific storage area.

  Further, the control unit 103 calculates one hash value (hereinafter referred to as a magazine hash value) for a combination of a plurality of disk hash values, and records this in the RF-ID tag 107 a of the magazine 107.

  Through the above processing, one disk hash value related to the combination of the address information and the hash value for the address information is recorded in advance on each of the plurality of optical disks 1. Further, one magazine hash value is recorded in advance in the RF-ID tag 107a.

  Next, processing for ensuring authenticity shown in FIG. 15 will be described. First, when reproducing the electronic data recorded on the plurality of optical disks 1, the control unit 103 reads the disk hash value stored in the management area (R1 or R2) of the optical disk 1 (S1d), and then the control unit 103 determines whether or not the disk hash values have been read from all the optical disks 1 (S2d).

  When the control unit 103 obtains a negative result in this determination, the control unit 103 proceeds to step S1d and reads the disk hash value of another optical disk 1 that has not been read yet. The control unit 103 repeats the processes of steps S1d and S2d until all the disk hash values of the optical disk 1 are read.

  On the other hand, when the control unit 103 obtains a positive result in the determination at step S2d, it uses a hash function that is a one-way function to perform an operation by a hash function on a combination of a plurality of read disk hash values. Then, one magazine hash value as a calculation result is calculated (S3d).

  Then, the control unit 103 reads the magazine hash value recorded in advance in the RF-ID tag 107a of the magazine 107 (S4d), and compares the read magazine hash value with the magazine hash value calculated in step S3d. It is determined whether or not both hash values match (S5d).

  If the control unit 103 obtains a positive result in this determination, it determines that both hash values match and the electronic data recorded on the plurality of optical discs 1 to be reproduced has not been tampered with. The process ends. On the other hand, if the control unit 103 obtains a negative result in the determination at step S5d, the control unit 103 determines that the two hash values do not match and the electronic data recorded on the plurality of optical discs 1 to be reproduced has been falsified. To do. Therefore, the control unit 103 adds a mismatch flag to the response command output to the host computer 200 (S6d), and ends this process.

  Next, FIG. 16 shows the relationship between the host computer 200, the changer control device 101, and the recording / reproducing apparatus 10A performed when reproducing the optical disc 1 in relation to the above-described process for ensuring authenticity according to the present embodiment. The exchange of signals is shown. This processing is started when the host computer 200 outputs an instruction to reproduce the optical disc 1 to the changer control device 101.

  First, the host computer 200 outputs a command (hereinafter referred to as a disk hash value confirmation command) requesting confirmation of the disk hash values of the plurality of optical disks 1 (1-1) to the changer control device 101 together with a reproduction instruction. (S21). In response to this, the changer control apparatus 101 outputs a disk hash value confirmation command to the recording / reproducing apparatus 10A (S22). In response to this, the recording / reproducing apparatus 10A acquires a disk hash value from a specific area of the optical disk 1 (1-1), and outputs the acquired disk hash value to the changer control apparatus 101 (S23).

  The changer control device 101 and the plurality of recording / reproducing devices 10A perform the same exchanges as in steps S22 and S23 described above for the other optical discs 1 (1-2 to 1-4) (S24 to S29). When the exchange of the disk hash value confirmation command and the disk hash value is completed for 1-1 to 1-4), the changer control apparatus 101 is a command for notifying that the disk hash values for all of the optical disks 1 have been acquired (hereinafter, referred to as “hash disk value”) A disk hash value response command) is output to the host computer 200 (S30).

  Thereafter, the host computer 200 outputs a command (hereinafter referred to as a magazine hash value confirmation command) requesting confirmation of the magazine hash value recorded in the RF-ID tag 107a of the magazine 107 to the changer control apparatus 101 ( S31). In response to this, the changer control apparatus 101 reads the magazine hash value from the RF-ID tag 107a and outputs a command notifying that it has been read (hereinafter referred to as a magazine hash value response command) to the host computer 200 (S32). .

  Through the above exchange, the control unit 103 can acquire all the disk hash values of the plurality of optical disks 1 and one magazine hash value for the combination of the disk hash values. Based on one magazine hash value, it is possible to detect whether or not the electronic data has been tampered with by performing the above-described process for ensuring authenticity in FIG.

  In FIG. 16, the control unit 103 outputs a disk hash value response command and a magazine hash value response command to the host computer 200. However, the present invention is not limited to this, and the control unit 103 sends all the disks to the host computer 200. A hash value and a magazine hash value recorded in advance in the RF-ID tag 107a may be output. In this case, the host computer 200 that has acquired all the disk hash values and magazine hash values can detect whether or not the electronic data has been tampered with.

  As a modified example, FIG. 17 shows the data structure of each of the plurality of optical disks 1, and each of the plurality of optical disks 1 is further calculated by combining hash values calculated for files # 1 to # 3. Indicates that one disk hash value to be stored is stored. Also in this case, similarly to the above-described process for ensuring authenticity (see FIG. 15), one calculated for a combination of one disk hash value for each optical disk 1 and one disk hash value for each optical disk 1 Based on the magazine hash value, it is possible to detect whether the electronic data has been tampered with. In addition, the “last address” according to the first embodiment, the “next OPC start address” according to the second embodiment, the “recording time information” according to the third embodiment, and the fourth embodiment One disk hash value is calculated for each optical disk 1 for each “disk ID” or combination thereof according to the form, one magazine hash value is further calculated for the combination of disk hash values, and the calculated disk hash The presence or absence of falsification of electronic data may be detected based on the value and the magazine hash value.

  In the above-described process for ensuring authenticity (see FIG. 15), the magazine hash value is recorded in the RF-ID tag 107a in the pre-processing stage of the process for ensuring authenticity. For example, it may be recorded in the memory 4 of the recording / reproducing apparatus 10A, the nonvolatile memory 8, the storage circuit 104 of the changer control apparatus 101, or a database on the network. In this case, the control unit 103 of the changer control device 101 is prerecorded in the magazine hash value recorded in advance in the RF-ID tag 107a and the memory 4 of the recording / reproducing device 10A in the process for ensuring authenticity. It is also possible to detect the presence or absence of falsification of electronic data by comparing with a magazine hash value.

  The RF-ID tag 107a may request a predetermined password when there is an access request from the changer control device 101 for the magazine hash value recorded in the internal memory. In this case, the presence / absence of falsification of electronic data can be detected. For example, when any one of the plurality of optical disks 1 accommodated in the magazine 107 is taken out and replaced with another optical disk 1, the magazine hash value for the combination of the plurality of optical disks 1 and the RF-ID tag 107a are recorded in advance. The magazine hash value for the combination of the plurality of optical disks 1 does not match, and it can be detected that the replacement of the optical disk 1 has occurred.

  Even if the electronic data recorded in the plurality of optical discs 1 accommodated in the magazine 107 is altered and returned to the same magazine 107 by any method, the disc hash value calculated for each of the plurality of optical discs 1 is It differs from the disk hash value before electronic data alteration. Therefore, the magazine hash value calculated by the combination of the disk hash values after falsification of the electronic data does not match the hash value calculated for the file recorded in advance in the RF-ID tag 107a, and the falsification is made to the electronic data. Can be detected.

(5-4) Effects of this Embodiment As described above, according to this embodiment, a plurality of optical discs 1 are obtained by using one disc hash value for each of the plurality of optical discs 1 and one magazine hash value by a combination thereof. The presence or absence of falsification of electronic data recorded on the optical disc 1 can be detected, and the authenticity of the electronic data can be ensured.

(6) Other Embodiments In the above-described embodiment, the first hash value calculation unit, the second hash value calculation unit, and the hash value comparison unit according to the present invention are configured as shown in FIG. Although the case where it is applied to the control units 6A to 6D of the recording / reproducing apparatuses 10A to 10D or the control unit 103 of the recording / reproducing system 100 configured as shown in FIG. 12, the present invention is not limited to this. In other recording / reproducing apparatuses and recording / reproducing systems, the present invention can be widely applied to a control unit that comprehensively controls these operations. Moreover, in the recording / reproducing apparatuses 10A to 10D and the recording / reproducing system 100 configured as shown in FIG. 1, a first hash value calculating unit, a second hash value calculating unit, and a hash value comparing unit may be provided.

  The present invention can be applied to a recording / reproducing method and a recording / reproducing apparatus for recording / reproducing electronic data on one or a plurality of optical disks.

10A to 10D Recording / reproducing apparatus 1 Optical disk 2 Pickup 3 Spindle motor 4 Memory 5 Signal processing circuit 6A to 6D Control unit 7 Interface 8 Non-volatile memory 100 Recording / reproducing system 101 Changer control device 102 Network interface 103 Control unit 104 Storage circuit 105 Drive Interface 106 RF-ID Tag Reader / Writer 107 Magazine 107a RF-ID Tag 200 Host Computer

Claims (14)

In a recording / reproducing method for ensuring the authenticity of electronic data recorded on an optical disc,
A first step of calculating a first hash value from address information indicating a boundary between a recorded area and an unrecorded area in the optical disk when recording electronic data on the optical disk;
A second step of calculating a second hash value from the address information when reproducing the electronic data recorded on the optical disc;
A recording / reproducing method comprising: a third step of comparing the first hash value and the second hash value. 2. The recording / reproducing according to claim 1, wherein the address information is one of a start address, a final address, and a next recordable address indicating a boundary between a recorded area and an unrecorded area of electronic data. Method. The recording / reproducing method according to claim 2, wherein the address information is a next trial writing start address indicating a boundary between a recorded area and an unrecorded area as the trial writing area. In the first step, a fourth hash value is calculated from recording time information when electronic data is recorded on the optical disc,
In the second step, a fifth hash value is calculated from the recording time information,
The recording / reproducing method according to claim 3, wherein the fourth hash value and the fifth hash value are compared in the third step. In the first step, a sixth hash value is calculated from identification information for identifying the optical disc,
In the second step, a seventh hash value is calculated from the identification information,
The recording / reproducing method according to claim 4, wherein the sixth hash value and the seventh hash value are compared in the third step. In the first step, the calculated hash value is attached to the optical disk, a storage unit in the recording / reproducing apparatus for reproducing the optical disk, a database on a network connected to the recording / reproducing apparatus, or a magazine for housing the optical disk. Record in any of the non-volatile memories,
In the second step, a hash value is calculated from address information, recording time information and / or identification information recorded on the optical disc,
6. The recording / reproducing method according to claim 5, wherein, in the third step, the hash value recorded in the first step is compared with the hash value calculated in the second step. In a recording / reproducing method for ensuring the authenticity of electronic data recorded on a plurality of optical discs,
When recording electronic data on the plurality of optical discs, one hash value is calculated for each of the plurality of optical discs from address information indicating a boundary between a recorded area and an unrecorded area in the plurality of optical discs. A first step of calculating one more first hash value from each hash value combination;
When reproducing the electronic data recorded on the plurality of optical discs, one hash value is calculated for each of the plurality of optical discs from the address information, and one second value is further calculated from the calculated combination of hash values for each optical disc. A second step of calculating a hash value of
A recording / reproducing method comprising: a third step of comparing the first hash value and the second hash value. In a recording / reproducing apparatus for ensuring the authenticity of electronic data recorded on an optical disc,
A first hash value calculator that calculates a first hash value from address information indicating a boundary between a recorded area and an unrecorded area in the optical disk when recording electronic data on the optical disk;
A second hash value calculator that calculates a second hash value from the address information when reproducing the electronic data recorded on the optical disc;
A hash value comparison unit that compares the first hash value and the second hash value;
A recording / reproducing apparatus comprising: 9. The recording / reproducing according to claim 8, wherein the address information is any one of a start address, a final address, and a next recordable address indicating a boundary between a recorded area and an unrecorded area of electronic data. apparatus. The recording / reproducing apparatus according to claim 9, wherein the address information is a next trial writing start address indicating a boundary between a recorded area and an unrecorded area as the trial writing area. The first hash value calculator calculates a fourth hash value from recording time information when electronic data is recorded on the optical disc,
The second hash value calculation unit calculates a fifth hash value from the recording time information,
The recording / reproducing apparatus according to claim 10, wherein the hash value comparison unit compares the fourth hash value with the fifth hash value. The first hash value calculation unit calculates a sixth hash value from identification information for identifying the optical disc,
The second hash value calculation unit calculates a seventh hash value from the identification information,
The recording / reproducing apparatus according to claim 11, wherein the hash value comparison unit compares the sixth hash value with the seventh hash value. The first hash value calculation unit stores the calculated hash value in the optical disk, a storage unit in a recording / reproducing apparatus that reproduces the optical disk, a database on a network connected to the recording / reproducing apparatus, or a magazine that accommodates the optical disk. Record in any of the attached non-volatile memories,
The second hash value calculation unit calculates a hash value from address information, recording time information and / or identification information recorded on the optical disc,
The hash value comparison unit compares the hash value recorded by the first hash value calculation unit with the hash value calculated by the second hash value calculation unit. Recording and playback device. In a recording / reproducing apparatus for ensuring the authenticity of electronic data recorded on a plurality of optical disks,
When recording electronic data on the plurality of optical discs, one hash value is calculated for each of the plurality of optical discs from address information indicating a boundary between a recorded area and an unrecorded area in the plurality of optical discs. A first hash value calculation unit that calculates one more first hash value from a combination of hash values for each;
When reproducing the electronic data recorded on the plurality of optical discs, one hash value is calculated for each of the plurality of optical discs from the address information, and one second value is further calculated from the calculated combination of hash values for each optical disc. A second hash value calculation unit for calculating the hash value of
A hash value comparison unit that compares the first hash value and the second hash value;
A recording / reproducing apparatus comprising:

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