JP2017204704A - Validity guarantee method, validity guarantee system and validity guarantee program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee validity of a device or a software generating a content without requiring a trusted third party organization.SOLUTION: An application providing device 10 includes a signature public key transmission unit 103 transmitting an electronic signature public key for application to a block chain network 50b as transaction of block chain. The application includes a content information transmission unit 205 transmitting a content, encrypted with a secret key corresponding to the public key, at the generation timing of content, and the hash value of metadata to a block chain network 50b as transaction of block chain. When there is a public key related to a content generated by a predetermined application in the block chain network 50b, a content use terminal 30 includes a guarantee unit 303 for guaranteeing validity of the predetermined application.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for assuring the validity of a source / source of digital data.

  An electronic signature is a technique for ensuring that digital data has not been tampered with in a communication path. The most common method for realizing an electronic signature is to use public key cryptography. In other words, a hash value is calculated by applying a hash function to digital data, the hash value is encrypted with a secret encryption key, and the value is distributed along with a public decryption key and digital data. The receiver of the digital data decrypts the encrypted hash value using the public decryption key and compares it with the hash value obtained by applying the hash function to the digital data. In this case, it is guaranteed that there is no change in the digital data from the time when the owner of the secret encryption key encrypts the hash value.

  Furthermore, it is possible to prevent so-called man-in-the-middle attacks by inquiring and confirming who is the owner of the public key used in the electronic signature, and confirming who is the digital data sent by the person. It can be guaranteed.

Saito, “Bitcoin – digital megalithic currency without humans”, WIDE Technical-Report in 2013, WIDE Project, December 31, 2013

  It goes without saying that in a device or software that generates / transmits digital data, it is important to be able to guarantee that the generated digital data is generated from the device or software. If this requirement is to be realized by electronic signature, a trusted third party is required to ensure that the public key used is associated with the device or software. However, regarding the point that this third-party organization is necessary, there is a problem that the structure itself for satisfying the above requirements is complicated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to assure the validity of the generation means (device or software) that generates digital data without the need of a reliable third-party organization. .

  In order to solve the above-described problem, a validity guarantee method according to claim 1 is provided by a generating device that provides a generating device capable of generating digital data and a using device that uses the digital data. In the validity guaranteeing method for guaranteeing validity, the providing device includes a transmission step of transmitting a public key for electronic signature for the generating means to a block chain network as a block chain transaction, and the generating means includes digital data A transmission step of transmitting a hash value of digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction at the timing of generating The public key related to the digital data generated in When in the click chain network, comprising a guaranteed steps to guarantee the validity of the predetermined generation means, and summarized in that.

  Further, the validity guarantee method according to claim 2 is a validity guarantee method for guaranteeing the validity of the generation means, which is performed by a providing apparatus that provides generation means capable of generating digital data and a block chain network. The providing apparatus includes a transmission step of transmitting a public key for electronic signature for the generation unit to a block chain network as a block chain transaction, and the generation unit corresponds to the public key at a timing when digital data is generated. A transmission step of transmitting a hash value of digital data encrypted with a secret key to the block chain network as a block chain transaction, the block chain network including a public key corresponding to the transaction transmitted from a predetermined generation unit Already sent If so, and a guaranteed steps to guarantee the validity of the predetermined generation means, and summarized in that.

  According to a third aspect of the present invention, there is provided a validity assurance method according to the first or second aspect, wherein the generation means is software or hardware for generating digital data.

  According to a fourth aspect of the present invention, there is provided a validity assurance system comprising a providing device that provides a generating means capable of generating digital data, and a utilization device that uses the digital data, and the validity guaranteeing the validity of the generating means. In the security guarantee system, the providing device includes a transmission unit that transmits a public key for electronic signature for the generation unit to a block chain network as a block chain transaction, and the generation unit generates digital data at a timing A transmission unit configured to transmit a hash value of digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction, wherein the using device generates digital data generated by a predetermined generation unit; The public key related to the blockchain network In some cases, including assurance unit to ensure the validity of the predetermined generation means, it is summarized as.

  Further, the validity guarantee system according to claim 5 comprises a providing device that provides a generation means capable of generating digital data, and a block chain network, and a validity guarantee system that guarantees the validity of the generation means. The providing apparatus includes a transmission unit that transmits a public key for electronic signature for the generation unit to a block chain network as a block chain transaction, and the generation unit corresponds to the public key at a timing when digital data is generated. A transmission unit that transmits a hash value of digital data encrypted with a secret key to the block chain network as a block chain transaction, the block chain network including a public key corresponding to a transaction transmitted from a predetermined generation unit Has already been sent If you are provided with a guaranteed portion to ensure the validity of the predetermined generation means, and summarized in that.

  Further, the validity guarantee system according to claim 6 is the validity guarantee system according to claim 4 or 5, wherein the generation means is software or hardware for generating digital data.

  A gist of a validity guarantee program according to claim 7 is to cause a computer to function as the validity guarantee system according to any one of claims 4 to 6.

  According to the present invention, it is possible to guarantee the validity of a device or software that generates digital data without the need of a reliable third party.

It is a figure which shows the whole structure of the correctness guarantee system which concerns on 1st Embodiment. It is a figure which shows the processing operation of the correctness assurance system which concerns on 1st Embodiment. It is a figure which shows the whole structure of the validity guarantee system which concerns on 2nd Embodiment. It is a figure which shows the processing operation of the validity guarantee system which concerns on 2nd Embodiment. It is a figure which shows the whole structure of the validity guarantee system which concerns on 3rd Embodiment. It is a figure which shows the processing operation of the correctness guarantee system which concerns on 3rd Embodiment. It is a figure which shows the whole structure of the correctness guarantee system which concerns on 4th Embodiment. It is a figure which shows the processing operation of the correctness assurance system which concerns on 4th Embodiment.

  In blockchain technology, which is the core technology of digital virtual currency that has been attracting attention in recent years, the contents of digital data exchanged within the network can be confirmed by any participant and exchanged as transactions. It has a feature that it is virtually impossible to falsify the contents of the digital data (Non-patent Document 1).

  Therefore, in the present invention, by applying this blockchain technology, a device or software provider that generates and transmits digital data at the timing when the device or software is manufactured or distributed to the blockchain network in the device or software. Information including a public key used in an electronic signature is transmitted as a block chain transaction. Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.

<First Embodiment>
In the first embodiment, software (hereinafter referred to as an application) is used as generation means for generating digital data. FIG. 1 is a diagram showing an overall configuration of a validity assurance system 1 according to the first embodiment. The validity guarantee system 1 uses an application providing device 10 that provides an application capable of generating digital data, an application operation terminal 20 that operates the application, and digital data (hereinafter, content) generated by the application. Content use terminal 30. The application providing device 10, the application operation terminal 20, and the content use terminal 30 can communicate with each other via the Internet 50a, and are further connected to the block chain network 50b.

  The application providing apparatus 10 is an apparatus that provides an application that can generate digital data. Specifically, as shown in FIG. 1, an application generation unit 101 that generates the application, a signature key generation unit 102 that generates a key pair for electronic signature for the application, and a public key of the key pair (= Public decryption key) is transmitted to the blockchain network 50b as a blockchain transaction, the signature public key transmitting unit 103, the providing destination information holding unit 104 holding the application providing destination, and the private key ( And an application distribution unit 105 that distributes to the provider including a secret encryption key).

  The application operation terminal 20 is an arbitrary terminal that operates an application distributed from the application providing apparatus 10. For example, a smartphone, a tablet, a personal computer, or the like. As shown in FIG. 1, the distributed application includes, in the application operating terminal 20, specifically, a content generation unit 201 that generates content, a metadata acquisition unit 202 that acquires metadata of the content, A hash value calculation unit 203 that calculates the hash value of the content and the metadata, a signature private key holding unit 204 that holds a digital signature private key generated by the application providing device 10, and encryption using the private key And a content information transmission unit 205 that transmits the hash value to the block chain network 50b as a block chain transaction.

  The content use terminal 30 is an arbitrary terminal that uses content generated by a predetermined application operation terminal. For example, as with the application operation terminal 20, a smartphone, a tablet, a personal computer, or the like. Specifically, as shown in FIG. 1, a content receiving unit 301 that receives content from a predetermined application operating terminal, and registration information corresponding to the content (encrypted with a public key and a private key for electronic signature) A hash value) from the blockchain network 50b, a guarantee unit 303 that guarantees the validity of the predetermined application operating terminal (≈app) based on the presence or absence of registration information corresponding to the content, It is configured with.

  Next, the block chain network 50b will be described. The block chain network 50b is configured in a peer-to-peer type in which a plurality of participant terminals used by each participant are connected to each other, and there is no terminal that plays a central management role. In each participant terminal, the block generation device 40 of FIG. 1 operates, and when the transaction corresponding to the transaction information reaches a certain time interval or a certain number, it tries to collect it as a block, and when the block is successfully generated or another block When a new block is received from the generation device, it is chained to the current block chain held by the block chain holding unit 403. When a new block is received from another block generation device, the block and the transaction contained in the block are verified, and only when it is recognized as valid. This makes it possible for all block generators to each have a unique absolute block chain that records transaction information for all participants. By providing this function, as described at the beginning, various pieces of information related to contents exchanged as a transaction (in this embodiment, a public key for electronic signature and a hash value encrypted with a private key) are falsified. It becomes virtually impossible. Therefore, the block chain network 50b functions as a reliable third party organization. The block chain network 50b is a network that can be constructed by a known method. For details on the mechanism, function, and effect of the block chain network 50b, see Non-Patent Document 1 and the like. Further, in this embodiment, in order to facilitate understanding of the invention, the block chain network 50b is expressed as a network having a different system from the Internet 50a in FIG. 1, but the block chain network 50b is usually on the Internet. Formed as an overlay network.

  In the present embodiment, the block generation device 40 receives a transaction related to the public key for electronic signature transmitted from the application providing device 10, and is a hash value encrypted with the private key transmitted from the application operation terminal 20. A transaction receiving unit 401 that receives a transaction related to the transaction, a block generation unit 402 that generates a block corresponding to each transaction, and a block chain holding unit 403 that connects (= registers) and holds each block in a block chain. The block transmission / reception unit 404 that transmits the generated block to another block generation device or receives the block transmitted from the other block generation device, and refers to the block of the block chain that is held, and the predetermined content Public key or private key for electronic signature corresponding to A registration information transmitting unit 405 for transmitting the encrypted hash value as the registration information, and includes a.

  Next, with reference to FIG. 2, an example of the processing operation of the validity guarantee method for guaranteeing the validity of the application in the validity guarantee system 1 described above will be described. This is a process for ensuring that content generated by a certain application is certainly generated by the application (regular application), and is performed by the content use terminal 30 that uses the content. Each time the application providing device 10 provides an application for generating content, the application providing apparatus 10 generates a key pair for electronic signature that is different for each application, and uses the private key of the key as a secure area of the application. Shall be stored. Here, it is assumed that the third party cannot obtain the secret key from the secure area. Hereinafter, a shooting application for image shooting is used as an example of the application.

  First, the application providing apparatus 10 blocks the public key for the purpose of publishing the public key for electronic signature used in the photographing application at the timing when the key pair for electronic signature for the photographing application to be provided is generated. It is transmitted as a block chain transaction to the network 50b (step S101).

  At this time, the transaction is received by the block generation device 40 of the block chain network 50b, and the block generation device 40 generates a block of the transaction and connects (= registers) the block to the block chain. Note that the ID of the photographing application is associated with the public key for electronic signature registered here.

  Next, the application providing apparatus 10 stores the electronic signature private key in a secure area of the imaging application, and distributes the imaging application in which the private key is registered to a predetermined providing destination via the Internet 50a (step S102). ).

  Next, when a photographer who wants to use the currently-captured shooting app installs the shooting app on his terminal (= app operation terminal 20) and shoots, the shooting app generates the content and A hash value with the metadata attached to the content is calculated, an electronic signature (encrypted with a secret key) is applied to the hash value, and it is transmitted to the block chain network 50b as a block chain transaction (step S103).

  At this time, the transaction is also received by the block generation device 40 of the block chain network 50b, and the block generation device 40 generates a block of the transaction and connects (= registers) the block to the block chain. The hash value encrypted with the secret key registered here is also associated with the ID of the photographing application.

  Next, when the user wants to use the content generated by the application operation terminal 20, the user downloads the content and the metadata of the content to his terminal (= content use terminal 30) (step S104). Here, the method for obtaining content and metadata is arbitrary, and transmission, distribution, and the like from the application operation terminal 20 can be considered in addition to downloading.

  Thereafter, in order to verify whether or not the downloaded content is generated by a legitimate shooting application, the content use terminal 30 encrypts with the public key and private key for electronic signature corresponding to the ID of the shooting application included in the content The converted hash value is acquired from the block chain network 50b (step S105), and the authenticity of the downloaded content and metadata is verified (step S106).

  Specifically, the content use terminal 30 can acquire at least the public key for electronic signature from the block chain network 50b, that is, if at least the public key for electronic signature is registered in the block chain network 50b, It is assumed that the content generated by the photographing application of the application operation terminal 20 is photographed by the regular photographing application, and the validity of the photographing application is guaranteed. In other words, if the corresponding public key is registered in the block chain, the target content is identified as a content generated by a regular shooting application, that is, the validity of the shooting application is affirmed. At this time, when the hash value encrypted with the secret key can be acquired from the block chain network 50b, the validity of the photographing application may be affirmed. On the other hand, if the corresponding public key is not registered in the block chain, the validity of the shooting application is denied.

  Thereafter, the content use terminal 30 calculates a hash value of the downloaded content and metadata, and encrypts it with the private key obtained using the public key for electronic signature obtained from the block chain network 50b. The hash value is decrypted, and the two hash values are compared to determine whether they match. If they match, it is ensured that the downloaded content was taken with a legitimate shooting application, and the authenticity of the downloaded content and metadata is verified. On the other hand, if they do not match, the authenticity of the content and metadata is denied.

  As described above, according to the present embodiment, the application providing apparatus 10 includes the signature public key transmission unit 103 that transmits the public key for electronic signature for the application to the block chain network 50b as a block chain transaction. Includes a content information transmission unit 205 that transmits a content encrypted with a secret key corresponding to the public key and a hash value of metadata to the block chain network 50b as a block chain transaction at a timing when the content is generated. The use terminal 30 includes a guarantee unit 303 that guarantees the validity of the predetermined application when the public key related to the content generated by the predetermined application is in the blockchain network 50b. Content without the need for It is possible to guarantee the validity of the generated application.

<Second Embodiment>
In the second embodiment, an apparatus (hereinafter referred to as a content generation apparatus) is used as generation means for generating digital data. FIG. 3 is a diagram showing an overall configuration of the validity assurance system 1 according to the second embodiment. The validity guarantee system 1 includes a content generation device providing device 10 ′, a content generation device 20 ′, a content usage terminal 30, and a block generation device 40.

  The content generation device providing device 10 ′ is a device that provides a content generation device capable of generating content. It corresponds to the application providing device 10 described in the first embodiment, and includes a content generation device manufacturing unit 101 ′ instead of the application generation unit 101 and the application distribution unit 105. Specifically, as shown in FIG. 3, a content generation device manufacturing unit 101 ′ that manufactures the content generation device including a private key for electronic signature and a key pair for electronic signature for the content generation device are generated. Signature key generation unit 102 ', a signature public key transmission unit 103' for transmitting a public key of the key pair to the block chain network 50b as a block chain transaction, and a provision for holding a provision destination of the content generation device And a destination information holding unit 104 ′. The content generation device manufacturing unit 101 ′ can be realized by any manufacturing system that manufactures the content generation device. The manufactured content generation apparatus is, for example, a hardware encoder configured with an LSI, a chip, or the like.

  The content generation device 20 ′ in FIG. 3 is a content generation device manufactured by the content generation device manufacturing unit 101 ′ of the content generation device providing apparatus 10 ′. The content generation apparatus 20 ′ has the same function as the application described in the first embodiment. Specifically, the content generation unit 201 ′, the metadata acquisition unit 202 ′, and the hash value calculation unit 203 ', A signature private key holding unit 204', and a content information transmission unit 205 '.

  The content use terminal 30 and the block generation device 40 have the same functions as those described in the first embodiment.

  Next, with reference to FIG. 4, an example of processing operation of the validity guarantee method for guaranteeing the validity of the content generation apparatus in the above-described validity guarantee system 1 will be described.

  First, the content generation device providing device 10 ′ has the purpose of publishing the public key for electronic signature used in the content generation device at the timing when the key pair for electronic signature for the content generation device to be provided is generated. The public key is transmitted as a block chain transaction to the block chain network 50b (step S201). Note that the ID of the content generation apparatus is associated with the public key for electronic signature registered here.

  Next, the manufacturer of the content generation device (for example, the chip manufacturer for hardware encoding) stores the electronic signature private key in a secure area of the content generation device and provides it to a predetermined destination (step). S202).

  Next, the provided content generation device 20 ′ calculates a hash value between the content and metadata attached to the content at the timing of generating the content, and an electronic signature (with a secret key) is applied to the hash value. (Encryption) is performed and transmitted to the block chain network 50b as a block chain transaction (step S203). The ID of the content generation apparatus is also associated with the public key for electronic signature registered here.

  Next, when the user wants to use the content generated by the content generation device 20 ′, the user downloads the content and the metadata of the content to his / her terminal (= content usage terminal 30) (step S204). .

  Thereafter, the content use terminal 30 verifies whether the downloaded content has been generated by a legitimate content generation device, so that the public key and private key for electronic signature corresponding to the ID of the content generation device included in the content are included. The hash value encrypted in (1) is acquired from the block chain network 50b (step S205), and the authenticity of the downloaded content and metadata is verified (step S206).

  Specifically, the content use terminal 30 can acquire at least the public key for electronic signature from the block chain network 50b, that is, if at least the public key for electronic signature is registered in the block chain network 50b, It is assumed that the content generated by the content generation device 20 ′ is taken by a regular content generation device, and the validity of the content generation device is guaranteed. That is, it is specified that the content is generated by a regular content generation device.

  As described above, according to the present embodiment, the content generation device providing device 10 ′ transmits the public key for electronic signature for the content generation device to the block chain network 50b as a block chain transaction. The content generation apparatus 20 ′ transmits the content encrypted with the secret key corresponding to the public key and the hash value of the metadata to the block chain network 50b as a block chain transaction at the timing when the content is generated. The content information transmission unit 205 ′, and the content use terminal 30 guarantees the validity of the predetermined content generation device when the public key relating to the content generated by the predetermined content generation device is in the block chain network 50b. Do Since comprises a testimony unit 303 can be without the need for reliable third party, to ensure the validity of the content generation apparatus for generating a content.

<Third Embodiment>
In the first embodiment and the second embodiment, a person who wants to confirm the authenticity of the content himself confirms the validity of the content generation source (app, content generation device) based on the block chain. explained. On the other hand, in the third and fourth embodiments, the person who creates the block (so-called minor) has already registered the corresponding public key in the block chain for the transaction transmitted from the generation source. A method of confirming the validity of the generation source based on whether or not it is present will be described.

  FIG. 5 is a diagram showing an overall configuration of the validity assurance system 1 according to the third embodiment. The validity assurance system 1 includes an application providing device 10, an application operation terminal 20, and a block generation device 40. The difference from FIG. 1 is that the content use terminal 30 is unnecessary, and the block generation device 40 includes a guarantee unit 406 instead of the registration information transmission unit 405.

  Next, a processing operation example of a validity guarantee method for guaranteeing the validity of an application in the blockchain network 50b in the above-described validity guarantee system 1 will be described with reference to FIG.

  First, the application providing apparatus 10 blocks the public key for the purpose of publishing the public key for electronic signature used in the photographing application at the timing when the key pair for electronic signature for the photographing application to be provided is generated. The data is transmitted as a block chain transaction to the network 50b (step S301). Note that the ID of the photographing application is associated with the public key for electronic signature transmitted here.

  Next, the application providing apparatus 10 stores the electronic signature private key in a secure area of the photographing application, and distributes the photographing application in which the private key is registered to a predetermined provision destination via the Internet 50a (step S302). ).

  Next, when a photographer who wants to use the currently-captured shooting app installs the shooting app on his terminal (= app operation terminal 20) and shoots, the shooting app generates the content and A hash value with the metadata attached to the content is calculated, an electronic signature (encrypted with a secret key) is applied to the hash value, and it is transmitted to the block chain network 50b as a block chain transaction (step S303). Note that the ID of the photographing application is also associated with the hash value encrypted with the secret key transmitted here.

  Next, in order to verify whether the hash value encrypted with the secret key is generated by a regular shooting application, the block generation device 40 publishes an electronic signature corresponding to the shooting application ID of the hash value. The key is acquired from the block chain holding unit 403 and verified based on whether or not the public key for electronic signature is acquired, that is, whether or not the public key for electronic signature is already registered (step S304).

  Specifically, if the public key for electronic signature can be obtained, that is, if the public key for electronic signature is registered in the block chain, the block generation device 40 encrypts with the private key received in step S303. It is assumed that the converted hash value is generated by a regular photographing application, and the validity of the photographing application is guaranteed. That is, the hash value generated by the regular photographing application is specified. Thereafter, when the validity is guaranteed, a block of a transaction related to the hash value encrypted with the secret key is generated and linked to the block chain. As a result, the transaction related to content generation registered in the block chain includes only those for which the validity of the photographing application is confirmed.

  As described above, according to the present embodiment, the application providing apparatus 10 includes the signature public key transmission unit 103 that transmits the public key for electronic signature for the application to the block chain network 50b as a block chain transaction. Includes a content information transmission unit 205 that transmits the content encrypted with the secret key corresponding to the public key and the hash value of the metadata to the block chain network 50b as a block chain transaction at the time when the content is generated. The generation device 40 includes a guarantee unit 406 that guarantees the validity of the predetermined application when the public key corresponding to the transaction transmitted from the predetermined application has already been transmitted. Content generation without the need for It is possible to guarantee the validity of the Li.

<Fourth embodiment>
In the fourth embodiment, in the case of the third embodiment, a content generation device is used as a generation unit that generates digital data. FIG. 7 is a diagram showing an overall configuration of the validity assurance system 1 according to the fourth embodiment. Similar to FIG. 3, the validity guarantee system 1 includes a content generation device providing device 10 ′, a content generation device 20 ′, and a block generation device 40. The difference from FIG. 3 is that the content use terminal 30 is not required, and the block generation device 40 includes a guarantee unit 406 instead of the registration information transmission unit 405.

  Next, with reference to FIG. 8, an example of the processing operation of the validity guarantee method for guaranteeing the validity of the block generation device in the block chain network 50b in the above-described validity guarantee system 1 will be described.

  First, the content generation device providing device 10 ′ has the purpose of publishing the public key for electronic signature used in the content generation device at the timing when the key pair for electronic signature for the content generation device to be provided is generated. The public key is transmitted to the block chain network 50b as a block chain transaction (step S401). The ID of the content generation device is associated with the public key for electronic signature transmitted here.

  Next, the manufacturer of the content generation apparatus stores the private key for electronic signature in a secure area of the content generation apparatus and provides it to a predetermined providing destination (step S402).

  Next, the provided content generation device 20 ′ calculates a hash value between the content and metadata attached to the content at the timing of generating the content, and an electronic signature (with a secret key) is applied to the hash value. (Encryption) is performed and transmitted to the block chain network 50b as a block chain transaction (step S403). The ID of the content generation device is also associated with the hash value encrypted with the secret key transmitted here.

  Next, the block generation device 40 verifies whether the hash value encrypted with the secret key is generated by a legitimate content generation device, and for the electronic signature corresponding to the ID of the photographing application of the hash value. The public key is acquired from the block chain holding unit 403 and verified based on whether or not the public key for electronic signature is acquired, that is, whether or not the public key for electronic signature is already registered (step S404).

  Specifically, if the public key for electronic signature can be obtained, that is, if the public key for electronic signature is registered in the block chain, the block generation device 40 encrypts with the private key received in step S303. It is assumed that the converted hash value is generated by a regular content generation device, and the validity of the content generation device is guaranteed. That is, the hash value generated by the regular content generation device is specified.

  As described above, according to the present embodiment, the content generation device providing device 10 ′ transmits the public key for electronic signature for the content generation device to the block chain network 50b as a block chain transaction. The content generation apparatus 20 ′ transmits the content encrypted with the secret key corresponding to the public key and the hash value of the metadata to the block chain network 50b as a block chain transaction at the timing when the content is generated. The block generation device 40 guarantees the validity of the predetermined content generation device when the public key corresponding to the transaction transmitted from the predetermined content generation device has already been transmitted. Guarantee 406 Because provided, it is possible without the need for reliable third party, to ensure the validity of the content generation apparatus for generating a content.

  Finally, the application providing device 10, the application operation terminal 20, the content use terminal 30, the block generation device 40, the content generation device provision device 10 ′, and the content generation device 20 ′ described in each embodiment have an arithmetic function such as a CPU. And a computer having a storage function such as a memory. It is also possible to create a validity guarantee program for causing a computer to function as each of these devices and a storage medium for the validity guarantee program.

1 ... Legitimacy assurance system 10 ... Application providing device (providing device)
DESCRIPTION OF SYMBOLS 10 '... Content production | generation apparatus provision apparatus 101 ... Application production | generation part 101' ... Content production | generation apparatus manufacturing part 102, 102 '... Signature key generation part 103, 103' ... Public key transmission part for signature (transmission part)
104, 104 '... providing destination information holding unit 105 ... application distribution unit 20 ... application operation terminal 20' ... content generation device (generation means)
201, 201 '... content generation unit 202, 202' ... metadata acquisition unit 203, 203 '... hash value calculation unit 204, 204' ... signature private key holding unit 205, 205 '... content information transmission unit (transmission unit)
30 ... Content use terminal (use device)
301: Content reception unit 302 ... Registration information acquisition unit 303 ... Guarantee unit (guarantee unit)
DESCRIPTION OF SYMBOLS 40 ... Block generation apparatus 401 ... Transaction reception part 402 ... Block generation part 403 ... Block chain holding | maintenance part 404 ... Block transmission / reception part 405 ... Registration information transmission part 406 ... Guarantee part (guarantee part)
50a ... Internet 50b ... Blockchain network S101 to S106, S201 to S206, S301 to S304, S401 to S404 ... step

Claims (7)

In a validity guarantee method for guaranteeing the validity of the generating means, which is performed by a providing apparatus that provides generating means capable of generating digital data and a utilization apparatus that uses the digital data,
The providing device includes:
A transmission step of transmitting a public key for electronic signature to the generation means to the block chain network as a block chain transaction,
The generating means includes
A transmission step of transmitting a hash value of the digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction at a timing when the digital data is generated;
The utilization device is:
When the public key related to the digital data generated by the predetermined generation means is in the blockchain network, the guarantee step of guaranteeing the validity of the predetermined generation means,
A validity guarantee method characterized by that. In a validity guarantee method for guaranteeing the validity of the generation means, which is performed by a providing apparatus that provides generation means capable of generating digital data and a block chain network,
The providing device includes:
A transmission step of transmitting a public key for electronic signature to the generation means to the block chain network as a block chain transaction,
The generating means includes
A transmission step of transmitting a hash value of the digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction at a timing when the digital data is generated;
The blockchain network is
When a public key corresponding to the transaction transmitted from the predetermined generation unit has already been transmitted, the security step includes a guarantee step for guaranteeing the validity of the predetermined generation unit.
A validity guarantee method characterized by that. The generating means includes
3. The validity guarantee method according to claim 1, wherein the validity guarantee method is software or hardware for generating digital data. In a validity guarantee system comprising a providing device that provides a generating means capable of generating digital data, and a utilization device that uses the digital data, and guarantees the validity of the generating means,
The providing device includes:
A transmission unit that transmits a public key for electronic signature to the generation means to the block chain network as a block chain transaction;
The generating means includes
A transmission unit that transmits a hash value of digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction at a timing when the digital data is generated;
The utilization device is:
When the public key related to the digital data generated by the predetermined generation unit is in the block chain network, the guarantee unit for guaranteeing the validity of the predetermined generation unit,
A validity guarantee system characterized by that. In a validity guarantee system comprising a providing device for providing a generation means capable of generating digital data and a block chain network, and guaranteeing the validity of the generation means,
The providing device includes:
A transmission unit that transmits a public key for electronic signature to the generation means to the block chain network as a block chain transaction;
The generating means includes
A transmission unit that transmits a hash value of digital data encrypted with a secret key corresponding to the public key to the block chain network as a block chain transaction at a timing when the digital data is generated;
The blockchain network is
When a public key corresponding to the transaction transmitted from the predetermined generation unit has already been transmitted, a guarantee unit that guarantees the validity of the predetermined generation unit is provided.
A validity guarantee system characterized by that. The generating means includes
6. The validity guarantee system according to claim 4, wherein the validity guarantee system is software or hardware for generating digital data.   A validity guarantee program for causing a computer to function as the validity guarantee system according to claim 4.

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