JP2018182710A - Electronic certification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic certification system enabling simplified processing for verification of reliability while improving the reliability.SOLUTION: An electronic certification system guarantees reliability of data provided from a first terminal device such as a server 1 to a second terminal device such as a client 3, etc., using a trail registered in a block chain 2. The first terminal device includes: trail registration means 102 which registers, to the block chain 2 as trails, information related to at least one of the first terminal device, the administrator of the first terminal device, and a program which is operated on the first terminal device to exchange data with the second terminal device, and data, to acquire the trails of being a block, generated by the registration, by a return from the block chain 2; and trail provision means 103 which transmits the trails to the second terminal device.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electronic certification system that secures the reliability of data such as a public key used in a public key infrastructure.

  In the past, a public key infrastructure has been widely used to securely perform communications via the Internet. This utilizes the property that data encrypted by a public key can be decrypted only by a secret key, and data encrypted by a secret key can be decrypted only by a public key.

  However, due to its characteristics, there is a risk that information will be illegally obtained if a third party provides a public key by impersonating the intended communication partner. In order to avoid it, a mechanism using electronic certificates is used.

  As an example, the case of performing communication using a public key infrastructure between the server and the client will be described. FIG. 14 is a diagram showing the flow of processing when preparing an electronic certificate in advance on the server side.

  The server first generates its own private key and public key in step S801. Here, the generated secret key needs to be strictly managed so that it does not leak outside

  In the following step S802, the server sends a signature request to the certificate authority. Here, the certificate authority is an organization that ensures that the electronic certificate is legitimate by performing electronic signature, and the legitimacy is determined by the issuance of a certificate by a higher-level certificate authority or the like. Secured. In addition, the signature request includes the public key of the server generated in step S801, the information of the server holder, the information used by the client when accessing the server such as the FQDN and IP address of the server, etc. , Request creation of an electronic certificate by electronic signature on the information.

  Then, in step S803, the electronic certificate of the server is generated by the electronic signature by the certificate authority. Here, more specifically, the digital signature by the certificate authority is performed by encrypting the hash value of the information included in the signature request with the secret key of the certificate authority itself. Then, in step S804, the electronic certificate is returned to the server.

  After the server's electronic certificate is prepared by the above process, the certificate is used for the process shown in FIG. 15 in the server-client communication. First, in step S901, when there is a connection request from the client, the server transmits its electronic certificate to the client in step S902.

  The client that has received the electronic certificate confirms the certificate authority that has made the electronic signature on the electronic certificate from the content, and in step S903, requests the public authority for verification of the electronic signature to the certificate authority.

  In step S904, the public key of the certificate authority is provided from the certificate authority to the client, and the client verifies the electronic signature in step S905. This utilizes the characteristics of the public key and the private key as described above, that is, the digital signature is decrypted with the public key of the certificate authority, and it is confirmed whether the original hash value etc. can be correctly obtained. It is something to do.

  Then, if the verification of the electronic signature is successful in step S 905, the client trusts the electronic certificate to be legitimate, and communicates with the server thereafter. As communication with the server, for example, when transmitting data from the client to the server, data is encrypted with the public key included in the electronic certificate, and decryption is performed only with the server having the corresponding private key. It sends data in a state where it can not do so. Also, when it is necessary to secure two-way communication between the server and the client, similarly, processing for transmitting the client-side public key to the server is performed.

  Although omitted for simplicity of explanation here, the client acquires the electronic certificate of the certificate authority and verifies it in order to verify whether the certificate authority itself is credible. Processing is performed, and finally, it is determined that the electronic certificate is trustworthy on the premise that the root certificate registered in the client is trustworthy.

  The above is the rough flow of the preparation of the electronic certificate when using the public key infrastructure, and the processing at the start of communication between the server and the client. In addition to the transmission of the public key, for example, the electronic certificate is used to digitally sign the document such as an e-mail, thereby securing the source and the content of the document without alteration. Is also used. As described above, security of reliability using electronic certificates is used in the exchange of various data for which reliability is required for the sender and its contents, etc. Furthermore, a system to which this is applied is also developed. ing.

  For example, in a system in which a plurality of nodes participate in Patent Document 1, a distributed authentication system that enhances the resistance to an attack on a certificate authority by performing an operation as a certificate authority by a plurality of representative nodes among them. Have been described. In this configuration, a plurality of representative nodes cooperate to perform electronic signature using the secret key of the representative key, but no node in the representative nodes holds the secret key of the representative key itself. Thus, the system is configured such that the secret key of the representative key used by the system participant for the electronic signature can not be known.

  In addition, according to Patent Document 2, in order to be able to distinguish between an electronic signature made by a digital signature generator and an electronic signature made by a third party spoofing an electronic signature generator, a log of the electronic signature can be used. A system is described which is configured to record and to verify the log when verifying a digital signature.

JP, 2008-186064, A Unexamined-Japanese-Patent No. 2004-40830

  The conventional trust model using an electronic certificate is based on the premise that a certificate authority that performs electronic signature can be trusted. Therefore, if the leak of the secret key used for the electronic signature by the certificate authority to the outside occurs, the electronic signature by the certificate authority will be meaningless at all.

  This is the same as in the system described in Patent Document 1, even when the role of the certificate authority is shared by a plurality of nodes, and in a configuration in which the secret key used for the electronic signature is not managed on a single node. Even if it exists, it can not be absolutely determined that leakage of the secret key does not occur, and if the configuration is such that the trust is secured by the electronic signature using it, the trust model collapses due to the leakage of the secret key. In the point that it ends, it can be said that it has the same problem as the above-mentioned prior art.

  Further, according to the system described in Patent Document 2, even when the secret key used for the electronic signature by the certificate authority leaks to the outside, the electronic signature is properly performed by referring to the log of the electronic signature. Although it is possible to determine whether or not it is a problem, there arises a problem that the verification process at the client becomes complicated. That is, even with a trust model using a conventional electronic certificate, processing such as verification of the electronic certificate to be actually verified and verification of the electronic certificate of the certificate authority that has made the electronic signature is required. Furthermore, since the verification of the log of the electronic signature is also required, the processing cost on the client increases.

  Therefore, it is an object of the present invention to provide an electronic proof system capable of simplifying the process for verifying the reliability while improving the reliability.

In order to solve the above problems, the electronic certification system according to the present invention is
An electronic certification system for securing the reliability of data provided from a first terminal device to a second terminal device with a trail registered in a block chain,
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device; Trail registration means for registering the data as the trail in the block chain and acquiring the trail, which is a block generated by the registration, by returning the block chain.
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The second terminal apparatus may determine that the data is reliable when the trail provided by the trail providing unit is registered in the block chain.

  In this manner, data provided from the first terminal device such as a server is registered in the block chain, and the second terminal device such as the client acquires it, thereby deleting or overwriting data in the block chain. It is possible to provide reliable data because of the inability to In addition, as in a system using a conventional electronic certificate, processing such as decryption of an electronic signature by a public key on the receiving side of data such as a client or calculation of a hash value can be omitted. Communication and processing can be greatly reduced.

Another form of the electronic certification system according to the present invention is
A digital certificate system registered in a data store by a first terminal device with a trail registered in a block chain and ensuring the reliability of data provided to the second terminal device,
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device Trail registration means for registering in the block chain as the trail and acquiring the trail, which is a block generated by registration, by returning from the block chain;
Store registration means for associating the trail with the data and registering the trail in the data store;
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The second terminal device is characterized in that, when the trail provided by the trail providing means is registered in the block chain, the second terminal device acquires the data from the data store using the trail. Do.
As described above, by configuring the trail as a block chain and the data for which the reliability is to be secured in a data store, more diverse data can be obtained while securing the reliability using the characteristics of the block chain. Can be provided.

Another form of the electronic certification system according to the present invention is
An electronic certification system for securing the reliability of data contained in an electronic certificate provided to a second terminal device by a first terminal device with a trail registered in a block chain And
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device Trail registration means for registering in the block chain as the trail and acquiring the trail, which is a block generated by registration, by returning from the block chain;
An electronic certificate in which generation of the electronic certificate and registration in the electronic certificate store by associating the trail acquired by the return from the block chain by the trail registration unit with the electronic certificate are performed Registration means,
Verification of validity of the trail registered in the block chain, acquisition of the electronic certificate corresponding to the trail from the electronic certificate store, and transmission of the electronic certificate to the second terminal device And providing electronic certificate providing means,
The second terminal device may extract the data from the electronic certificate provided from the electronic certificate providing unit.
As described above, by verifying the validity of the trail on the side of the first terminal such as the server and providing data in the form of an electronic certificate to the second terminal such as the client, The system can be widely used by clients and the like that can handle conventional electronic certificates.

In a preferred embodiment of the present invention, the trail is not valid because there is a block in the block chain which is registered after the trail and which invalidate the trail.
By this, it is possible to realize a configuration in which the expiration date can be set and invalidated like a conventional electronic certificate while using a block chain having a characteristic that data deletion and overwriting are impossible. it can.

In a preferred embodiment of the present invention, the data is a public key of the first terminal device.
Thus, secure communication between terminal devices can be assisted by securing the reliability of the public key used for communication based on the public key basis.

  It is possible to provide an electronic certification system that can realize both the improvement of reliability using the characteristics of block chains and the reduction of processing weight for verification of reliability.

It is a block diagram of the electronic proof system which concerns on Embodiment 1 of this invention. It is a functional block diagram of the electronic certification system concerning Embodiment 1 of the present invention. It is a sequence diagram which shows the registration process of the trail and public key in Embodiment 1 of this invention. It is a sequence diagram which shows the process at the time of the communication start between the server-client in Embodiment 1 of this invention. FIG. 7 is a sequence diagram showing a trail revocation process according to the first embodiment of the present invention. It is a block diagram of the electronic proof system which concerns on Embodiment 2 of this invention. It is a functional block diagram of the electronic certification system concerning Embodiment 2 of the present invention. It is a sequence diagram which shows the registration process of the trail and public key in Embodiment 2 of this invention. It is a sequence diagram which shows the process at the time of the communication start between the server-client in Embodiment 2 of this invention. It is a block diagram of the electronic proof system which concerns on Embodiment 3 of this invention. It is a functional block diagram of the electronic certification system concerning Embodiment 3 of the present invention. It is a sequence diagram which shows the registration process of the trail and electronic certificate in Embodiment 3 of this invention. It is a sequence diagram which shows the process at the time of the communication start between the server-client in Embodiment 3 of this invention. It is a sequence diagram which shows the issuing process of the electronic certificate by the conventional certificate authority. It is a sequence diagram which shows the process at the time of the communication start between server-clients in the conventional system.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of the electronic certification system according to the present embodiment. In the electronic certification system according to the present embodiment, a server 1, a block chain 2, and a plurality of clients 3a to 3d (hereinafter simply referred to as the client 3 when there is no need to distinguish) are the Internet etc. The network NW is configured to be communicable. Then, the block chain 2 is used to secure the reliability of the public key of the server 1 provided from the server 1 to the client 3 in order to communicate using the public key infrastructure between the server 1 and the client 3. It is done.

  The block chain 2 is originally used as a distributed ledger in bitcoins, which is a virtual currency, and is constituted by a large number of nodes, but here, for the sake of simplicity, FIG. Shown as a single component, as shown in FIG.

  The block chain 2 is configured by a chain of data called a block, and each block contains information of the hash value of the previous block, so when any block is tampered, Inconsistencies occur in the chain relationship. Also, since this is a distributed system composed of a large number of nodes, it has the characteristic that such unauthorized falsification processing and block deletion can not be performed by the operation of a single node or the like. . In the present specification, a block generated by registering data such as information on the server 1 and the public key of the server 1 is referred to as a trail.

  FIG. 2 shows a functional block diagram of the electronic certification system according to the present embodiment. As shown here, the server 1 registers in the block chain 2 the key generation means 101 for generating the public key and the secret key of the server 1, the public key generated by the key generation means 101, information on the server 1, etc. The trail registration unit 102 for acquiring the trail from the block chain 2, the trail provision unit 103 for providing the trail to the client 3, and the public key using the public key and the secret key generated by the key generation unit 101. And service providing means 104 for providing a service using the base from the server 1 to the client 3.

  The server 1 may be connected to a computing device such as a CPU, a main storage device such as a random access memory (RAM), an auxiliary storage device such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory, and a network NW. A general computer device such as a server device provided with various input / output devices and the like including the means can be used. More specifically, programs for operating the server 1 as each means as described above are stored in advance in the auxiliary storage device or by the operation of the administrator of the server 1 or the like, and the programs are stored in the main storage device. The computer apparatus can be used as the server 1 in the electronic certification system according to the present embodiment by expanding the process above and performing arithmetic operations by the arithmetic device to control the input / output means. Although the configuration in which the server 1 is realized by a single computer device has been shown in the present embodiment, the present invention is not limited to this. For example, the server 1 may be realized by a plurality of computer devices, such as a configuration in which the service providing means 104 is provided in another computer device.

  Also as the client 3, a general computer device provided with an arithmetic device, a main storage device, an auxiliary storage device, various input / output devices including connection means to the network NW, etc. can be used. In FIG. 1, the personal computer 3a, the tablet terminal 3b, the network camera 3c, and the in-vehicle device 3d are shown as an example, but the present invention is not limited to this, and the client 3 can be used for other various computer devices. It can be used as

<Trail registration processing>
FIG. 3 is a sequence diagram showing a flow of trail registration processing in the block chain 2 by the server 1. First, in step S101, the key generation unit 101 performs generation processing of the secret key and the public key of the server 1. Here, more specifically, after the generation of the secret key, it may be used to generate the corresponding public key. The public key generated here is passed to the trail registration means 102 for registration in the block chain 2. On the other hand, the secret key needs to be handled so that it does not leak to the outside.

  In step S102, the trail registration unit 102 makes a trail registration request to the block chain 2. This means that information such as information on the server 1 and information on the administrator of the server 1, information on the service providing means 104 for performing communication on a public key basis using this public key later, and the public key to the block chain 2 It is a process of requesting generation of a block by registration.

  In step S103, based on the request from the trail registration unit 102, registration processing of information related to the server 1 and the like to the block chain 2 and the public key, that is, block generation processing is performed. Then, the block generated here is returned to the server 1 as a trail in step S104. By the above processing, registration processing of the trail to the block chain 2 by the server 1 is completed.

  The trail registration in the block chain 2 is preferably managed by an organization that has received an appropriate audit, such as an organization that has obtained an Information Security Management System (ISMS). By doing so, it is possible to prevent registration of an inappropriate trail in the block chain 2 and the like, and to further improve the reliability of the electronic certification system according to the present embodiment. In addition, even if an unauthorized trail is registered, the trace of the unauthorized registration remains on the block chain 2 in a state where it can not be deleted, so that it can be used as a countermeasure for grasping the situation and preventing recurrence. .

<Public key provision processing>
FIG. 4 is a sequence diagram showing the flow of processing between the server 1 and the client 3 at the start of communication using a public key infrastructure. First, in step S201, a connection request is transmitted from the client 3 to the server 1. In step S202, the server 1 having received the request transmits the trail to the client 3 by the trail providing unit 103.

  In step S203, the client 3 having received the trail performs confirmation processing of the validity of the trail to the block chain 2. This is to inquire whether the trail is present on the block chain 2.

  Then, in step S204, the block chain 2 sends a reply to the client 3 about the validity of the trail. Here, if the trail is present on the block chain 2, the client 3 exchanges the public key of the server 1 also included in the trail with the server 1 identified by the information included in the trail. It can be determined that it is safe to use and communicate.

  After the client 3 confirms the security of the public key of the server 1, the data encrypted by the secret key of the server 1 is transmitted to the client 3, and the client 3 decrypts it with the public key of the server 1, The client 3 encrypts data with the public key of the server 1 and transmits it to the server 1, and the server 1 performs communication using a public key infrastructure such as decrypting it with the secret key of the server 1. be able to.

  As described above, verification of the electronic signature such as conventional electronic certificate verification is performed by adopting a configuration in which verification of the reliability of the public key is performed by confirmation processing of whether or not there is a trail on the block chain 2 No need for processing such as acquisition of the public key for decryption, decryption of the electronic signature or calculation of the hash value until the root certificate is reached, and the processing amount and communication amount on the client 3 are greatly reduced. be able to.

<Trail revocation process>
In some cases, it may be necessary to change the public key of the server 1 and delete the trail in which the old public key is registered from the block chain 2 after, for example, a predetermined period has elapsed. However, as described above, the feature of the block chain 2 is that it does not allow overwriting or deletion of blocks. Therefore, in such a case, the trail is invalidated by the process shown in the sequence diagram of FIG.

  First, in step S301, the server 1 sends a request for revocation processing of trails registered in the past to the block chain 2. That is, it is a request for the creation of a new block, which indicates that the particular trail is invalid. Then, in step S302, such a block is generated on the block chain 2, and the trail revocation process ends.

  In this manner, when the trail is invalidated, the trail is validated from the client 3 to the block chain 2 in step S203 when communication between the server 1 and the client 3 is started. If the block exists on the block chain 2 but there is a block that invalidates it, it is determined that the trail is invalid.

  In this way, it is possible to perform processing such as invalidating the public key while using the block chain 2 having a characteristic that blocks can not be overwritten or deleted.

<Security collateral for other data>
In the present embodiment, an example is shown in which the reliability of the public key of the server 1 used for communication between the server 1 and the client 3 is secured. However, the present invention is not limited to this. It is possible to guarantee the credibility of various data, such as the credibility of which has been secured by the letter.

  For example, if it is ensured that a document such as an e-mail has not been tampered with, in place of the generation of the secret key and the public key in step S101 in the trail registration processing described with reference to FIG. The hash value of the block chain 2 may be calculated and registered in the block chain 2 in the subsequent steps S102 and S103. As described above, the hash value of the document is registered in the block chain 2 and the trail is provided together with the provision of the document, whereby the receiving side calculates the hash value of the document, and the result If the contents of the trail match, it can be determined that the document has not been tampered with.

  In the present embodiment, an example is shown in which a server device is used as the server 1 and a so-called client device such as a personal computer is used as the client 3. However, the words "server" and "client" in this specification Does not specify such a specific device, but for a plurality of devices that make up the client server model, a device that plays a role of transmitting data is a “server”, and a device that plays a role of receiving data It is simply called "client". That is, if the application is to prove that the client device such as a personal computer or mobile device is valid, such as a client certificate, to the server device etc. of the connection destination, the information related to itself The client device that transmits the role of “server” and the server device that receives and verifies the role of “server” respectively play the role of “client”.

  Furthermore, not only for the client server model, but also for simply exchanging data between two or more devices via an arbitrary physical storage medium or the like, with respect to the terminal device of the data provision destination, It is possible to secure the credibility of data. That is, in the case of exchanging data from one terminal device to another terminal device, as described in the present embodiment, even in the case of providing a trail via a network, it is possible to use a physical storage medium. Even in the case of providing a trail in any other manner, the electronic certification system according to the present invention can be applied to secure the reliability of data.

  As described above, according to the electronic certification system according to the present embodiment, the signature on the client side (that is, the receiving side of data) is used by utilizing the characteristic that deletion or overwriting of data in the block chain is not possible. Verification processing can be omitted, and high reliability can be secured.

  Also, as in the conventional trust model using electronic certificates, processing such as request for digital signature to the certificate authority and confirmation of requester and request content by the certificate authority is omitted, and trail registration in block chain 2 is performed. Can be used to secure credibility. As a result, for a large number of terminal devices, particularly when there is a need to secure the legitimacy of a large amount of data, such as when each terminal device has a public key / private key, significant effects can be expected.

Second Embodiment
Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to the drawings. In addition, about the fundamentally same component as Embodiment 1 mentioned above, the same code | symbol is attached | subjected and the description is simplified. FIG. 6 is a block diagram of the electronic certification system according to the present embodiment. As shown here, in the electronic certification system according to the present embodiment, the public key store 4 including the public key storage unit 401 in addition to the server 1, the block chain 2 and the client 3 is communicably connected via the network NW. ing.

  FIG. 7 is a functional block diagram of the electronic certification system according to the present embodiment. As shown here, in addition to the key generation unit 101, the trail registration unit 102, the trail provision unit 103, and the service provision unit 104, the server 1 requests the public key store 4 to register the public key. A registration unit 105 is provided.

<Trail registration processing>
FIG. 8 is a sequence diagram showing a flow of trail registration processing in the block chain 2 and public key registration processing in the public key store 4 in the electronic certification system according to the present embodiment. First, in step S401, the key generation unit 101 performs generation processing of the secret key and the public key of the server 1.

  In step S402, trail registration processing is performed from the trail registration unit 102 to the block chain 2. In the present embodiment, here, block chain information such as information on the server 1 and information on the administrator of the server 1 and information on the service providing means 104 which performs communication on the public key basis using the public key of the server 1 later. This process is a process of requesting generation of a block by the registration to 2. The public key itself of the server 1 is not registered to the block chain 2. After step S402, block generation is performed in step S403, and is returned to the server 1 as a trail in step S404.

  After trail registration is performed in the block chain 2 in the processing up to this point, registration of a public key is requested from the server 1 to the public key store 4 in step S405. This request is for correlating the trail returned in step S404 with the public key generated in step S401 and requesting recording in the public key storage unit 401 provided in the public key store 4. In step S406, the requested public key store 4 records the trail and the public key in the public key storage unit 401.

  As a result of the above processing, information related to the server 1 is stored as a trail in the block chain 2 as a trail and the public key of the server 1 is stored in the public key store 4 in a state of being linked to the trail.

<Public key provision processing>
FIG. 9 is a sequence diagram showing the flow of processing between the server 1 and the client 3 at the start of communication using a public key infrastructure. The processes in steps S501 to S504 are the same as the processes in the first embodiment described with reference to steps S201 to S204 in FIG. 4 except that the trail does not include the public key itself.

  In the present embodiment, when the validity of the trail provided from the server 1 can be confirmed in the processing up to step S504, in step S505, the client 3 transmits the public key of the server 1 to the public key store 4 A request is made. Since the public key store 4 stores the public key of the server 1 linked to the trail, the client 3 transmits the trail provided by the server 1 to the block chain 2 in step S505. , And requests for the corresponding public key.

  Then, in step S506, the public key store 4 sends the public key of the server 1 as a response to the request from the client 3, and the process of providing the public key to the client 3 ends. As described above, the public key store 4 can be used to provide a public key to the client 3 without registering the public key itself in the block chain 2.

  The revocation processing of the public key can also be realized by registering a block indicating trail revocation on the block chain 2 as described with reference to FIG. 5 in the first embodiment. .

  Also in the present embodiment, the recording of the public key used by the server 1 in the public key store 4 is merely an example, and various other data can be used for the purpose of securing the reliability. In particular, when it is necessary to guarantee the reliability of relatively large data size data, it is preferable to use the configuration according to the present embodiment for storing data in a data store such as public key store 4. it can.

(Embodiment 3)
Hereinafter, Embodiment 3 of the present invention will be described in detail with reference to the drawings. In addition, about the fundamentally same component as Embodiment 1 mentioned above, the same code | symbol is attached | subjected and the description is simplified. FIG. 10 is a block diagram of the electronic certification system according to the present embodiment. As shown here, the electronic certification system according to the present embodiment allows the electronic certificate store 5 including the electronic certificate storage unit 501 to be communicable via the network NW in addition to the server 1, the block chain 2 and the client 3. It is connected.

  FIG. 11 is a functional block diagram of the electronic certification system according to the present embodiment. As shown here, in addition to the key generation unit 101, the trail registration unit 102, the trail provision unit 103, and the service provision unit 104, the server 1 performs electronic certification including the public key of the server 1 to the digital certificate store 5. The electronic certificate registration means 106 for requesting registration of a document, and the electronic certificate provision means 107 for providing the electronic certificate to the client 3 are provided.

<Trail registration processing>
FIG. 12 is a sequence diagram showing a flow of trail registration processing in the block chain 2 and electronic certificate registration processing in the electronic certificate store 5 in the electronic certification system according to the present embodiment. First, in step S601, the key generation unit 101 performs generation processing of the secret key and the public key of the server 1.

  In step S602, an electronic signature is performed on the public key of the server 1 generated in step S601, information on the server 1, and the like to generate an electronic certificate. In addition to the public key generated in step S601 in advance by the server 1 or by the generation processing by the key generation unit 101, the electronic signature here is a secret key for electronic signature (hereinafter referred to as a signature) separately from the private key. Prepare the public key of the server 1 generated in step S601 by using the private key for signature and the public key (hereinafter referred to as the public key for verification) for verifying the secret key To sign the included electronic certificate. That is, the electronic certificate generated here corresponds to a self-issued certificate that is self-signed by the server 1. Alternatively, the private key for signature and the public key for verification are not separately prepared, and the public key generated in step S601 is digitally signed with the private key generated in step S601 to generate a self-signed certificate. It is also good.

  In step S603, trail registration processing is performed from the trail registration unit 102 to the block chain 2. In the present embodiment, here, block chain information such as information on the server 1 and information on the administrator of the server 1 and information on the service providing means 104 which performs communication on the public key basis using the public key of the server 1 later. This process is a process of requesting generation of a block by registration to 2. The electronic certificate itself is not registered to the block chain 2.

  After trail registration in the block chain 2 in the processing up to this point, registration of the electronic certificate is requested from the server 1 to the electronic certificate store 5 in step S606. This request links the trail returned in step S605 with the electronic certificate generated in step S602, and requests recording in the electronic certificate storage unit 501 of the electronic certificate store 5 It is. The requested electronic certificate store 5 records the trail and the electronic certificate on the electronic certificate storage unit 501 in step S607.

  As a result of the above processing, information related to the server 1 is stored as a trail in the block chain 2 and the electronic certificate of the server 1 is stored in the electronic certificate store 5 in a state of being linked to the trail.

<Public key provision processing>
FIG. 13 is a sequence diagram showing the flow of processing between the server 1 and the client 3 at the start of communication using a public key infrastructure. First, in step S701, a connection request is transmitted from the client 3 to the server 1. In step S702, the server 1 that has received it checks the block chain 2 whether or not its own trail exists in a valid state.

  In step S703, when an answer is obtained that the own trail is valid, the process proceeds to step S704, the electronic certificate linked to the trail is requested, and the electronic certificate is the server 1 in step S705. Sent to. Then, in step S706, the electronic certificate is transmitted from the server 1 to the client 3, and in step S707, verification processing of the electronic certificate is performed.

  In the verification process in step S 707, if the electronic certificate is signed using the signature private key, that is, if the electronic certificate is a self-issued certificate, the server 1 makes the verification public. It is verified by being provided with a key, and is included in the electronic certificate if it is a self-signed certificate signed by the private key of the server 1 paired with the public key contained in the certificate. Verification is performed using the public key.

  Here, since the electronic certificate provided by the server 1 is a self-issued electronic certificate or a self-signed electronic certificate, the server 1 is registered in advance as a server that can be trusted by the server 1. There is a need.

  An electronic certificate including the public key of the server 1 is provided to the client 3 by the above-described procedure. Note that the revocation processing of the electronic certificate is also realized by registering a block that indicates revocation of the trail on the block chain 2 as described in the first embodiment with reference to FIG. 5. it can.

  Also in the present embodiment, the recording of the electronic certificate including the public key used by the server 1 in the electronic certificate store 5 is merely an example, and other various data are used for the purpose of securing the reliability. can do. That is, for a document such as the e-mail exemplified above, the electronic certificate including the hash value is registered in the electronic certificate store 5 and provided to the client 3.

  In the electronic certification system according to the present embodiment, processing such as reception of a trail from the server 1 by the client 3 and confirmation of the validity of the trail from the client 3 to the block chain 2 is unnecessary, and the client 3 Since it is only necessary to be able to verify a self-issued certificate and a self-signed certificate in the same manner as a scheme using an electronic certificate, the electronic certificate system according to the present invention is realized using a wider range of clients 3. It is possible to

1 server 101 key generation means 102 trail registration means 103 trail provision means 104 service provision means 105 public key registration means 106 digital certificate registration means 107 digital certificate provision means 2 block chain 3 client 4 public key store 401 public key storage unit 5 Electronic certificate store 501 Electronic certificate storage unit NW network

In order to solve the above problems, the electronic certification system according to the present invention is
An electronic certification system for securing the reliability of data provided from a first terminal device to a second terminal device with a trail registered in a block chain,
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device; , registers and the data, the prior Symbol block chain, and trail registering means for the trail to get a return from the block chain is a block generated by the registration,
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The second terminal device determines that the data is reliable when the trail provided by the trail providing unit is registered as the block in the block chain. .

Another form of the electronic certification system according to the present invention is
A digital certificate system registered in a data store by a first terminal device with a trail registered in a block chain and ensuring the reliability of data provided to the second terminal device,
The first terminal device is
The first terminal device, the administrator of the first terminal device, information about at least one of said first run on the terminal device program for exchanging the data with the second terminal device register before Symbol block chain, and trail registration means for acquiring the return of the trail is a block generated by the registration from the block chain,
Store registration means for associating the trail with the data and registering the trail in the data store;
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The second terminal device acquires the data from the data store using the trail when the trail provided by the trail providing unit is registered as the block in the block chain. It is characterized by
As described above, by configuring the trail as a block chain and the data for which the reliability is to be secured in a data store, more diverse data can be obtained while securing the reliability using the characteristics of the block chain. Can be provided.

Another form of the electronic certification system according to the present invention is
An electronic certification system for securing the reliability of data contained in an electronic certificate provided to a second terminal device by a first terminal device with a trail registered in a block chain And
The first terminal device is
The first terminal device, the administrator of the first terminal device, information about at least one of said first run on the terminal device program for exchanging the data with the second terminal device register before Symbol block chain, and trail registration means for acquiring the return of the trail is a block generated by the registration from the block chain,
An electronic certificate in which generation of the electronic certificate and registration in the electronic certificate store by associating the trail acquired by the return from the block chain by the trail registration unit with the electronic certificate are performed Registration means,
Verification of validity of the trail registered as the block in the block chain, acquisition of the electronic certificate corresponding to the trail from the electronic certificate store, and the second terminal device of the electronic certificate Providing electronic certificate providing means for
The second terminal device may extract the data from the electronic certificate provided from the electronic certificate providing unit.
As described above, by verifying the validity of the trail on the side of the first terminal such as the server and providing data in the form of an electronic certificate to the second terminal such as the client, The system can be widely used by clients and the like that can handle conventional electronic certificates.

Claims (5)

An electronic certification system for securing the reliability of data provided from a first terminal device to a second terminal device with a trail registered in a block chain,
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device; Trail registration means for registering the data as the trail in the block chain and acquiring the trail, which is a block generated by the registration, by returning the block chain.
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The electronic certification system is characterized in that the second terminal device determines that the data is reliable if the trail provided by the trail providing means is registered in the block chain. system. A digital certificate system registered in a data store by a first terminal device with a trail registered in a block chain and ensuring the reliability of data provided to the second terminal device,
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device Trail registration means for registering in the block chain as the trail and acquiring the trail, which is a block generated by registration, by returning from the block chain;
Store registration means for associating the trail with the data and registering the trail in the data store;
Trail provision means for transmitting the trail obtained by the return from the block chain by the trail registration means to the second terminal device;
The second terminal device is characterized in that, when the trail provided by the trail providing means is registered in the block chain, the second terminal device acquires the data from the data store using the trail. To be an electronic certification system. An electronic certification system for securing the reliability of data contained in an electronic certificate provided to a second terminal device by a first terminal device with a trail registered in a block chain And
The first terminal device is
Information regarding at least one of the first terminal device, an administrator of the first terminal device, and a program operating on the first terminal device and exchanging data with the second terminal device Trail registration means for registering in the block chain as the trail and acquiring the trail, which is a block generated by registration, by returning from the block chain;
An electronic certificate in which generation of the electronic certificate and registration in the electronic certificate store by associating the trail acquired by the return from the block chain by the trail registration unit with the electronic certificate are performed Registration means,
Verification of validity of the trail registered in the block chain, acquisition of the electronic certificate corresponding to the trail from the electronic certificate store, and transmission of the electronic certificate to the second terminal device And providing electronic certificate providing means,
An electronic certification system characterized in that the second terminal device extracts the data from the electronic certificate provided by the electronic certificate providing means.   The said trail is considered as invalid by the fact that the block which invalidates the said trail registered in the said block chain after the said trail exists, and which is characterized by the above-mentioned. Electronic certification system described in. The electronic certification system according to any one of claims 1 to 4, wherein the data is a public key of the first terminal device.