JP2008186064A - Distributed authentication system, distributed authentication method, and distributed authentication program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distributed authentication system, capable of improving the resistance to attack on an authentication station by suppressing the security risk that easy identification of the location of the authentication station facilitates the attack thereon. <P>SOLUTION: The distributed authentication system includes one or more nodes. A predetermined number of nodes of nodes which participate in the distributed authentication system are representative nodes which represent the distributed authentication system. The representative nodes issue, in cooperation with each other, a representative key used for electronic signature of the distributed authentication system, a distributed authentication system electronic certificate, a private key used for electronic signature of each node which participates in the distributed authentication system, and an electronic certificate for each node which participates in the distributed authentication system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a distributed authentication system, a distributed authentication method, and a distributed authentication program, and in particular, verifies the validity of an electronic certificate attached to a message and decrypts the electronic signature using the public key of the electronic certificate. The present invention relates to an authentication technique for verifying the validity of the message.

  On the Internet, not only text contents but also various contents such as images, sounds, and videos have been directly exchanged between users by a file sharing network using P2P (Peer to Peer) technology.

  However, if the participation in the file sharing network is completely free, it becomes a cause of illegal node participation and illegal content distribution. Therefore, conventionally, this has been avoided by applying an authentication technique to the file sharing network.

  For example, some use a certificate authority. In this method, a certificate is issued in advance by a certificate authority in order for a node to participate in a file sharing network, and mutual authentication is performed between nodes using an electronic signature.

As prior art documents related to the present invention, there are the following.
JP 2004-159298 A JP 2004-171274 A JP 2004-254271 A JP 2006-101277 A JP 11-015374 A

  However, the technique using the conventional certificate authority described above has a problem that the certificate authority is likely to be an attack target because it exists in a specific location on the network. The reason is that the certificate authority exists at a specific location on the network so that it can be connected from nodes that exist everywhere, and therefore the location of the certificate authority is also revealed to malicious attackers. This is due to the security risk of being easily attacked.

  An object of the present invention is to provide a distributed authentication system capable of suppressing the security risk that the location of a certificate authority is known and being easily attacked, and improving the resistance to attacks on the certificate authority.

  To achieve the above object, a distributed authentication system according to the present invention is a distributed authentication system composed of one or a plurality of nodes, and a predetermined number of nodes among the nodes participating in the distributed authentication system are A representative node representing the distributed authentication system, and the representative nodes cooperate with each other to thereby represent a representative key used in an electronic signature of the distributed authentication system, a distributed authentication system electronic certificate, and a node participating in the distributed authentication system A personal key used in the electronic signature of the node and an electronic certificate of a node participating in the distributed authentication system are issued.

  The distributed authentication method according to the present invention is a distributed authentication system including one or a plurality of nodes, and a predetermined number of nodes among the nodes participating in the distributed authentication system are representative nodes representing the distributed authentication system. The representative nodes cooperate with each other to represent a representative key used in an electronic signature of the distributed authentication system, a distributed authentication system electronic certificate, a personal key used in an electronic signature of a node participating in the distributed authentication system, A distributed authentication method for a distributed authentication system that issues an electronic certificate of a node participating in the distributed authentication system, comprising: (A) starting participation in the distributed authentication system; and (B) the distributed authentication system. When the total number of nodes participating in the system is less than a predetermined number, the step of performing the consensus mode, (C) the distributed authentication system When the total number of participating nodes is greater than or equal to a predetermined number, the representative mode operation is an operation for a general node other than the representative node, and (D) the representative mode operation is for the representative node. Performing an operation; (E) performing an operation for confirming an electronic signature of a message received from another node; (F) performing an initial operation of the representative node; and (G) the representative node. And (H) performing an operation when leaving the representative node, and (H) performing an operation when updating the representative node.

  According to the present invention, it is possible to provide a distributed authentication system capable of suppressing the security risk that the location of the certificate authority is known and being easily attacked and improving the resistance to attacks on the certificate authority.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  In this embodiment, in a situation where there is no independent certificate authority, a node that participates in the file sharing network cooperates to become a certificate authority, and a key (representative key) for the electronic signature of the node that newly participates in the file sharing network , A personal key) and a digital authentication (distributed authentication system electronic certificate, node electronic certificate) storage authentication system, distributed authentication method, and program.

  In this embodiment, the distributed authentication system electronic certificate corresponds to the certificate authority's electronic certificate, and includes the public key of the representative key, as will be described later, and the electronic signature of the distributed authentication system is the electronic signature of the certificate authority. Correspondingly, it is encrypted with the secret key of the representative key. Further, as will be described later, the electronic certificate of the node includes the public key of the private key and the electronic signature of the distributed authentication system, and the electronic signature of the node is encrypted with the private key of the private key. .

  Here, by decrypting the electronic signature of the distributed authentication system included in the electronic certificate of the node with the public key of the representative key included in the distributed authentication system electronic certificate, the validity of the electronic certificate of the node is verified. It becomes possible to verify. Further, the authenticity of the message can be verified by decrypting the electronic signature of the node added to the transmission message from the node with the public key of the personal key included in the electronic certificate of the node. Details thereof will be described later.

  The distributed authentication system of this embodiment is configured by one or a plurality of nodes. Among the nodes participating in the distributed authentication system, a prescribed number of nodes become representative nodes. The specified number of representative nodes cooperate with each other, so that the representative key of the distributed authentication system, the distributed authentication system electronic certificate, the personal key of the node participating in the distributed authentication system, and the node participating in the distributed authentication system It has a function to issue an electronic certificate.

  The node constituting the distributed authentication system of the present embodiment stores the node information including the receiving unit for receiving data sent from other nodes and the node list including the information of the nodes constituting the distributed authentication system in an updatable manner. And a node list, the mode of the distributed authentication system is a consensus mode when the total number of nodes participating in the distributed authentication system is less than a predetermined number, and the total number of nodes participating in the distributed authentication system is predetermined. A mode management unit that manages the representative mode when there are more than a number, a representative node function unit that operates as a representative node in the representative mode, and an operation when a general node other than the representative node is in the representative mode A general node function unit that performs operations common to the consensus mode and the representative mode, a representative node function unit, a general node function unit, and A signature adding unit that adds an electronic signature to the data to other nodes that are passed from passing function unit, a transmission unit for transmitting the data with an electronic signature is added to said another node, the.

  When the node is a general node, the general node function unit has a temporary key generation unit having a function of generating a temporary key, and a participation request to participate in the distributed authentication system. A participation operation unit having a function of transmitting a participation request to a certain node.

  When the node is a representative node, the representative node function unit cooperates with other representative nodes to generate a representative key for the distributed authentication system and a function for generating a distributed authentication system digital certificate, Other node electronic certificate generation unit having a function of receiving a participation request or an electronic certificate generation request from another node and generating a personal key and an electronic certificate of another node, a function of leaving the representative node, and the representative node Generates a random prime number that is the prime key of the representative key of the distributed authentication system and the secret key of the private key of the other node. A random prime number generation unit having a function of

  When the node is a general node or a representative node, the common function unit includes a keep alive operation unit having a function of exchanging a node list with another node by a keep alive operation, and an application using the distributed authentication system. From an application unit having a function to be performed, a personal key generation unit having a function of generating a private key of a private key from information that is a source of a private key of a private key received from a specified number of representative nodes, and other nodes An electronic signature confirmation unit having a function of confirming the validity of the electronic signature added to the received message.

  The receiving unit has a function of sending the received message to the mode management unit.

  The mode management unit has a function of reading a node list stored in the node information storage unit, a function of confirming the number of nodes participating in the distributed authentication system, and a function of confirming a mode of the distributed authentication system. . Further, the mode management unit has a function of managing the status of whether the own node is a representative node or a general node.

  The representative node cooperates with other representative nodes to receive a function for generating a distributed authentication system representative key and a distributed authentication system digital certificate, and a participation request or digital certificate generation request from another node. A function to generate a personal key and electronic certificate of a node, a function to leave the representative node, a function to designate a representative node when the number of representative nodes is less than the specified number, a representative key of the distributed authentication system, and others A function that generates a random prime number that is a prime key of a private key of a private key of a node, a function that exchanges a node list with another node by a keep alive operation, a function that implements an application that uses a distributed authentication system, and a specification A function for generating a private key of a private key from information that is a source of a private key of a private key received from several representative nodes, and a method for receiving a private key from other nodes. It has a function to check the validity of the electronic signature attached to sage, and.

  The node list includes node information of all nodes participating in the distributed authentication system and representative node information. The node information includes a node ID, a node IP address, a port number, representative node information, and old representative node information. The representative node information includes information indicating which node is the representative node representing the distributed authentication system. The old representative node information includes information on which representative node representative of the distributed authentication system was in the past.

  The temporary key is not a key issued by the distributed authentication system, but a key generated by each node. It is used for all messages sent to other nodes when newly participating in the distributed authentication system and in the consensus mode. Used for electronic signatures to be added.

  The key is a secret key or public key in the public key cryptosystem, and the key exists as a set of a secret key and a public key. The representative key of the distributed authentication system is the secret key and the representative key of the representative key. The private key of a certain node is composed of a private key of the private key and a public key of the private key.

  The representative key of the distributed authentication system is a key created by a specified number of representative nodes representing the distributed authentication system in cooperation with each other. Distributed authentication is performed on the node list and the electronic certificates of the nodes participating in the distributed authentication system. Used to add a system digital signature. However, the secret key of the representative key of the distributed authentication system is distributed and stored by a plurality of representative nodes, and no node on the distributed authentication system can know the secret key of the representative key of the distributed authentication system. On the other hand, the public key of the representative key of the distributed authentication system is disclosed on the distributed authentication system, and any node on the distributed authentication system can be referred to.

  An electronic certificate of a node participating in the distributed authentication system is a public key of a personal key created by a prescribed number of representative nodes representing the distributed authentication system in cooperation with each other, information on nodes participating in the distributed authentication system, and Add a digital signature with the representative key of the distributed authentication system to the public key of the private key created by the prescribed number of representative nodes representing the distributed authentication system and the digest information of the node information participating in the distributed authentication system. It is a thing.

  Digest information refers to summary information of the original information, and is generated by applying a one-way function to the original information.

  Further, the mode management unit periodically reads the node information stored in the node information storage unit, and has a function of confirming whether or not the number of nodes participating in the distributed authentication system is less than the prescribed number, When the number of nodes participating in the distributed authentication system is less than the prescribed number, the node is operated in the consensus mode, and when the number of nodes participating in the distributed authentication system is more than the prescribed number, the node is operated in the representative mode, Further, in the representative mode, the node is operated as a representative node when designated as a representative node, and the node is operated as a general node when not designated as a representative node.

  Further, the mode management unit confirms the node list stored in the node information storage unit in the consensus mode, and if the total number of nodes participating in the distributed authentication system has reached the specified number, the mode management unit represents the node. It has a function to shift to the mode.

  Further, the mode management unit instructs the representative node function unit to generate a representative key of the distributed authentication system, and the general node function unit rejoins the distributed authentication network and issues an electronic certificate issued by the distributed authentication system. And a function to instruct to obtain a key, a function to instruct the representative node function unit to electronically sign the node list using the secret key of the key, and an electronic signature by a specified number of representative nodes to the representative node function unit And a function for instructing to add an electronic signature using a representative key of the distributed authentication system to the completed node list.

  Further, the mode management unit has a function of distributing the received message to an appropriate functional unit.

  The participation operation unit has a function of transmitting a participation request to which a public key of a temporary key is added when the own node newly participates in the distributed authentication system, and a temporary attachment added to the participation request when the participation request is received. A function of confirming the electronic signature using the public key of the key and transmitting a participation response when there is no tampering. However, when the distributed authentication system is in the consensus mode, the participation operation unit adds the public key of the node's temporary key and the node list to the participation response, and the signature adding unit applies the electronic signature with the private key of the temporary key. After that, when a participation response is sent and the distributed authentication system is in the representative mode, a message to the effect that the participation request has been accepted is signed in the participation response, and an electronic signature is signed with the private key of the own node's private key. In addition, the participation operation unit reads the node list from the node information storage unit, confirms the representative node, and the electronic certificate added with the node information of the node that transmitted the participation request to a certain representative node It has a function of transmitting a generation request.

  The temporary key generation unit has a function of generating a temporary key and a function of storing the generated temporary key in the node information storage unit together with the node information of the own node.

  The random prime number generation unit receives a request from the representative key generation unit and another node electronic certificate generation unit, generates a random prime number, and generates a random prime number in the representative key generation unit and other node electronic certificate generation unit. And a function of passing a prime number.

  When the distributed authentication system is in the representative mode and the own node is the representative node, the representative key generation unit receives other instructions from the mode management unit to generate a representative key for the distributed authentication system. In cooperation with the representative node representing the distributed authentication system, the prime number generated by the random prime number generation unit is prime, using the multi-party protocol without informing the other nodes of the prime key public key information, The distributed authentication system has a function of generating a public key of a representative key and a function of storing a prime number used for generating a representative key until the node is no longer a representative node.

  Further, the representative key generation unit displays a representative of the distributed authentication system in the node list in which the electronic signature by the prescribed number of representative nodes is completed from the mode management unit when the distributed authentication system is the representative mode and the own node is the representative node. When an instruction is given to add an electronic signature with a key, the node list is linked with the representative nodes representing the other specified number of distributed authentication systems, without informing the other nodes of the information representing the prime key. Has a function of adding an electronic signature using the secret key of the representative key of the distributed authentication system.

  The representative node nominating / leaving function unit has a function of reading a node list from the node information storage unit and transmitting a representative node leaving request to another representative node when the own node is the representative node and wants to leave the representative node. When the node is a representative node, when a representative node leave request is received, a function to send a representative node leave response to the representative node that has sent the representative node leave request, and the number of representative nodes is less than the specified number In order to set the number of representative nodes to the specified number, a node list is read from the node information storage unit, a function for selecting an appropriate general node, and a representative node nomination confirmation message describing the node information of the selected general node Selected when the function to send to all the representative nodes and the representative node nomination confirmation message are received. If the representative node nomination confirmation response is received from all the representative nodes except for itself, the representative node nomination confirmation response including the availability information is confirmed. A function to send a node nomination request, a function to send a representative node nomination response including availability information, and a function to send a representative node nomination response when the node is a general node and receives a node representative node nomination request And a function of transmitting node information of a node to be a new representative node to all the representative nodes except the own node.

  Furthermore, the representative node nominating / leaving function unit repeats the above operations until the number of representative nodes reaches a specified number, and the representative node function unit uses the private key of the private key to digitally sign the node list. A function to instruct, and a function to instruct the old representative node, which was a representative node before the representative key is updated, to sign an electronic signature on a node list in which the electronic signature by the node that is the current representative node has been completed; A function to instruct the representative node function unit to add an electronic signature with the representative key of the distributed authentication system to a node list in which the electronic signature has been completed by the prescribed number of representative nodes and the prescribed number of old representative nodes, and the representative key It has a function of storing in a node information storage unit as a distributed authentication network electronic certificate in combination with a public key.

  When the distributed authentication system is in the representative mode and the local node is the representative node, the other node electronic certificate generator generates a random prime number generator in cooperation with other representative nodes when receiving an electronic certificate generation request. A function that generates a private key for a node described in an electronic certificate request using a multi-party protocol without informing other nodes of information that is a prime of a private key accompanying the electronic certificate. And a function for generating an electronic certificate from the node information of the node and the personal key in cooperation with the representative key generation unit, information and a public key as a source of the private key of the personal key, and the electronic certificate as an electronic certificate It has a function to transmit to the node described in the generation request.

  The keep alive operation unit transmits a keep alive message periodically to other nodes, a function for checking the connection of the communication path by receiving a keep alive message from other nodes periodically, and a keep alive Compare the node list added to the message with the node list read from the node information storage unit, update the node list to the latest information, and if there is no response for a certain period of time for the keep-alive message, the corresponding node is distributed authentication It is determined that the node has left the system, the node list is updated, the function to transmit the latest information to other nodes using the keep-alive operation, and the representative node is displayed in the node management unit when it is determined that the representative node has left. And a function of transmitting that the user has left.

  The application unit has a function of processing an application that uses the distributed authentication system.

  The private key generation unit is a function that generates a private key for a private key from a specified number of pieces of information that is the source of the private key of the private key received from a specified number of representative nodes, and the received public key and private key are valid. And a function for confirming the validity of the received electronic certificate.

  When receiving a message, the electronic signature confirmation unit confirms the message source, sends the electronic certificate issuance request of the message source node to the distributed authentication system, and the electronic certificate of the message source node. A function to send a distributed authentication system electronic certificate issuance request to the distributed authentication system and a distributed authentication system electronic certificate to confirm the electronic signature with the representative key of the distributed authentication system attached to the electronic certificate. When the public key of the representative key attached to the certificate is obtained, the electronic signature attached to the electronic certificate is decrypted with the public key, and the validity of the electronic certificate is confirmed. A function to check the validity of a message by decrypting the attached digital signature with the public key attached to the digital certificate, and the digital certificate from other nodes When a line request is received, the corresponding electronic certificate is read from the node information storage unit, and a function to send back an electronic certificate issuance response and when a distributed authentication system electronic certificate issuance request is received from another node, It has a function of reading out a corresponding public key from the node information storage unit and transmitting a distributed authentication system electronic certificate issuance response.

  The signature adding unit uses a temporary key stored in the node information storage unit when the distributed authentication system is in the consensus mode, adds a digital signature to a message from another functional unit, and performs electronic processing by the distributed authentication system. A function that uses a temporary key stored in the node information storage unit when a certificate has not been issued and adds a digital signature to a message from another function unit, and a case where the distributed authentication system is in consensus mode A function for adding an electronic signature to a message from another functional unit using a personal key stored in the node information storage unit when the electronic certificate is issued by the distributed authentication system .

  The transmitting unit has a function of receiving a message from the signature adding unit and transmitting the message to the destination node described in the message.

  The node information storage unit has a function of storing node information, a temporary key, an electronic certificate, a node list, and a distributed authentication network electronic certificate of the own node.

  The distributed authentication method of the distributed authentication system according to the present embodiment includes (A) a step of starting participation in the distributed authentication system, (B) a step of performing an operation in the consensus mode, and (C) an operation in the case of a general node. , (D) a step of performing an operation as a representative node, (E) a step of performing an operation for checking an electronic signature of a received message, and (F) performing an initial operation of the representative node. And (G) a step of performing an operation when updating the representative node, and (H) a step of performing an operation when leaving the representative node.

  (A) starting to participate in the distributed authentication system includes (A1) an initial state step, (A2) a step of generating a temporary key, (A3) a step of storing the temporary key and node information, (A4) a step of transmitting a participation request to another node already participating in the distributed authentication system, (A5) a step of confirming the mode of the distributed authentication system, and (A6) a participation request as a participation request response Receiving the temporary key and the node list of the node that transmitted the request, and updating the node list; (A7) reading the node list and checking whether the temporary keys of all the nodes described in the node list are held; , (A8) a step of receiving a participation response; (A9) information serving as a source of a private key of the private key from a specified number of representative nodes; A receiving certificates, and generating a private key from the information to be (A10) containing the private key private key received in step A9.

  The step of (B) performing the operation in the consensus mode includes (B1) an initial state step in the operation of the consensus mode, and (B2) a node and a node list participating in another distributed authentication system by the keep alive operation. And (B3) reading the node list and confirming whether or not the number of nodes participating in the distributed authentication system has reached a specified number.

  (C) The step of performing the operation for the general node includes (C1) the initial state step of the general node operation, and (C2) the node list is read, and the keep alive message with the node list added is sent to the other nodes. A transmission step; (C3) a step of receiving a keep-alive message with a node list added from another node; and (C4) a node list and its own node added to the keep-alive message received at step C3. Comparing the stored node lists and updating to the latest information; (C5) reading the node list and checking whether the number of nodes participating in the distributed authentication system has reached a prescribed number; and (C6 ) A step of receiving a participation request; and (C7) a node that has transmitted the participation request. On the other hand, a step of transmitting a participation response, (C8) a step of transmitting an electronic certificate creation request to an arbitrary representative node among the prescribed number of representative nodes, and (C9) receiving a representative node nomination request. And (C10) a step of selecting whether or not to become a representative node, and (C11) a step of transmitting a representative node nomination response to the node that has transmitted the representative node nomination request in step C9 in order to become a representative node. (C12) a step of adding a representative node rejection information and transmitting a representative node nomination response to the node that has transmitted the representative node nomination request in step C9 in order to refuse to become a representative node; C13) receiving an electronic certificate issuance request; and (C14) step. To node which has transmitted the digital certificate issuance request 13, and a step of transmitting the digital certificate issuance response added with the electronic certificate of the node.

  (D) The step of performing the operation at the time of the representative node includes (D1) an initial state step at the time of the representative node operation, and (D2) a keep alive message in which the node list is read and the node list is added to the other nodes. (D3) receiving a keep-alive message with a node list added from another node; (D4) the node list and its own node added to the keep-alive message received at step D3 (D5) reading the node list and confirming whether or not the number of nodes participating in the distributed authentication system has reached a predetermined number; D6) reading the node list and confirming that the representative node has not left; and (D ) If you want to leave the representative node, send a representative node leave request to other representative nodes; (D8) receive a representative node leave response; (D9) receive a join request; D10) a step of transmitting a participation response to the node that has transmitted the participation request; and (D11) a step of generating a random prime number that is information serving as a prime key of the private key of the node that has transmitted the participation request. (D12) collaborating with each other between the prescribed number of representative nodes and generating a public key of the personal key of the node that has transmitted the participation request; and (D13) cooperating with each other between the prescribed number of representative nodes, A step of generating an electronic certificate of the node that has transmitted the participation request; and (D14) generated in step D11. The information that is the source of the private key of the private key of the node that transmitted the participation request, the public key of the personal key of the node that transmitted the participation request generated in step D12, and the participation request generated in step D13 are transmitted. Transmitting the electronic certificate of the received node to the node that has transmitted the participation request; (D15) receiving the electronic certificate generation request; and (D16) receiving the representative node leaving request; (D17) a step of transmitting a representative node leaving response; (D18) a step of receiving a representative node nomination confirmation message; (D19) a step of transmitting a representative node nomination confirmation response; and (D20) an electronic certificate issuance request. Receiving, and (D21) issuing an electronic certificate in step D20 A step of transmitting an electronic certificate issuance response to which the electronic certificate of the own node is added to the node that has transmitted the request; (D22) a step of receiving a distributed authentication system electronic certificate issuance request; and (D23) step. And a step of transmitting a distributed authentication system electronic certificate issuance response added with the distributed authentication system electronic certificate to the node that has transmitted the distributed authentication system electronic certificate issuance request in D22.

  The step of (E) performing the operation for confirming the electronic signature of the received message includes (E1) an initial state step of the signature confirmation operation and (E2) transmitting an electronic certificate issuance request of the message transmission source node. (E3) a step of receiving an electronic certificate issuance response; (E4) a step of transmitting a distributed authentication system electronic certificate issuance request to the representative node; and (E5) a distributed authentication system electronic certificate issuance response. And (E6) using the public key of the representative key added to the electronic certificate of the distributed authentication system, decrypting the electronic signature added to the electronic certificate with the public key, and verifying the validity of the electronic certificate The message is decrypted with the public key attached to the digital certificate. And a step of confirming the validity.

  The step of (F) performing the initial operation of the representative node includes (F1) an initial state step during the initial operation of the representative node, and (F2) a random prime number serving as information serving as a prime key of the representative key of the distributed authentication system. (F3) a step of generating a public key of a representative key of the distributed authentication system in cooperation with each other between a predetermined number of representative nodes, and (F4) A step of performing an electronic signature using a private key; (F5) transmitting a node list that has been electronically signed to another representative node; and (F6) receiving a node list from the other representative node. (F7) Checking whether the electronic signatures of all the representative nodes are added to the node list received in step F6, and (F8) Completing the electronic signatures by all the representative nodes. Transmitting the node list to the remaining old representative node; (F9) receiving the node list to which the electronic signature of the remaining old representative node is added; and (F10) the node list received in step F9. A step of confirming whether an electronic signature by all the remaining old representative nodes has been added, and a step of (F11) creating a distributed authentication system electronic certificate by cooperating with each other between the prescribed number of representative nodes.

  (G) performing the operation when updating the representative node includes (G1) an initial state step during the representative node update operation, (G2) selecting a node to be newly represented as a representative node, and (G3) A step of transmitting a representative node nomination confirmation message to another representative node; (G4) a step of receiving a representative node nomination confirmation response; and (G5) a representative node nomination confirmation response received in step S-F4. (G6) a step of transmitting a representative node nomination request to the node selected in step G2, and (G7) from the node selected in step G2. , A step of receiving a representative node nomination response, and (G8) the representative node received in step G7. The de nomination response has ascertaining whether refuse to become the representative node message is added, a step of confirming whether reached (G9) Number number representative node provisions.

  (H) The step of performing the operation when leaving the representative node includes (H1) an initial state step at the time of leaving the representative node, and (H2) a node to which the electronic signatures of all the representative nodes are added from the representative node. The step of receiving the list, (H3) adding the electronic signature to the node list received in step H2, and (H4) transmitting the node list with the electronic signatures of all representative nodes added in step H2. And a step of transmitting the node list to which the electronic signature is added in step H3 to the representative node.

  The distributed authentication program of this embodiment is a program for causing a computer to execute the distributed authentication method.

  As described above, in the present embodiment, a prescribed number of nodes among the nodes participating in the distributed authentication system become representative nodes, issue a representative key of the distributed authentication system and its distributed authentication system electronic certificate, and distribute Issue personal keys and electronic certificates of nodes participating in the authentication system. The specified number of representative nodes share the process of issuing the key and electronic certificate by using a multi-party protocol in cooperation with each other, but cannot know the secret keys of other nodes. . If the total number of nodes is less than the specified number, the consensus mode is entered, no representative key is generated, and authentication is performed by exchanging temporary keys. In other cases, the representative mode is selected, the representative node is selected, the representative node is periodically changed, and the node that continues the representative node approves the node that becomes the new representative node, and the representative key is inherited.

  Therefore, according to the present embodiment, the following effects can be achieved.

  The first effect is that the attack resistance of the certificate authority is improved. The reason is that a specified number of nodes among the nodes participating in the distributed authentication system become representative nodes, issuing the representative key of the distributed authentication system and the distributed authentication system electronic certificate, and the private key of the node participating in the distributed authentication system And the issuance of digital certificates through the cooperation of a specified number of representative nodes with each other, and the flexibility of nominating and leaving the representative nodes to attack against attacks from malicious attackers This is because the authentication service can be continued without losing the function as the distributed authentication system by changing the representative node one after another even if the system is distributed.

  The second effect is that it is possible to provide an authentication service having the same level of security as when there is a specific certificate authority without a specific certificate authority. The reason is that a specified number of nodes among the nodes participating in the distributed authentication system become representative nodes, issuing the representative key of the distributed authentication system and the distributed authentication system electronic certificate, and the private key of the node participating in the distributed authentication system And the issuance of electronic certificates is achieved by the cooperation of a specified number of representative nodes with each other, and by assigning and leaving the representative nodes flexibly, it is equivalent to the case where a certificate authority exists in a specific location This is because it is possible to provide an authentication service with the safety of the above.

  First, a first embodiment of the present invention will be described in detail with reference to the drawings.

  Referring to FIG. 1, nodes constituting the distributed authentication system according to the present embodiment include a receiving unit 1, a mode management unit 2, a general node function unit 3, a representative node function unit 4, and a common function unit 5. A node information storage unit 8, a signature addition unit 6, and a transmission unit 7.

  The general node function unit 3 includes a participation operation unit 31 and a temporary key generation unit 32.

  The representative node function unit 4 includes a random prime number generation unit 41, a representative key generation unit 42, a representative node nomination / leaving function unit 43, and another node electronic certificate generation unit 44.

  The common function unit 5 includes a keep alive operation unit 51, an application unit 52, a personal key generation unit 53, and an electronic signature confirmation unit 54.

  The receiving unit 1 sends the received message to the mode management unit 2.

  The mode management unit 2 reads the node list stored in the node information storage unit 8, confirms the number of nodes participating in the distributed authentication system, and confirms the mode of the distributed authentication system. Further, the mode management unit 2 manages whether the own node is a representative node or a general node.

  Here, the mode of the distributed authentication system indicates a consensus mode and a representative mode.

  The consensus mode refers to node operation when the total number of nodes participating in the distributed authentication system is less than the prescribed number m. In the consensus mode, each node generates a temporary key and participates in the distributed authentication system. That is, in the consensus mode, there is no representative node that represents the distributed authentication system, and the nodes that participate each use a temporary key that is prepared by each node to authenticate each other.

  On the other hand, the representative mode refers to an operation of a node when the total number of nodes participating in the distributed authentication system is a predetermined number m or more. In the representative mode, m nodes among the nodes participating in the distributed authentication system operate as representative nodes representing the distributed authentication system, and the other nodes operate as general nodes.

  Here, the representative node is a node representing the distributed authentication system, and generates a representative key of the distributed authentication system, creates a key and electronic certificate of the node participating in the distributed authentication system, and designates the representative node. It is a node that plays the role of The representative node is periodically updated and may become a representative node for all nodes participating in the distributed authentication system.

  Here, the node list is a list of node information and representative node information of all nodes participating in the distributed authentication system. The node information is, for example, a node ID and a node IP address. The representative node information is information indicating which node is the representative node representing the distributed authentication system.

  Here, the temporary key is not a key issued by the distributed authentication system, but a key generated by each node. The temporary key is used for an electronic signature added to all messages transmitted to other nodes when newly participating in the distributed authentication system and in the consensus mode.

  Here, the key is a secret key and a public key in the public key cryptosystem, and exists as a set of the secret key and the public key. Therefore, the representative key of the distributed authentication system includes a secret key of the representative key and a public key of the representative key. Similarly, the private key of a certain node includes a private key of the private key and a public key of the private key.

  Here, the representative key of the distributed authentication system is a key created by the m representative nodes representing the distributed authentication system in cooperation with each other. The node list and the electronic certificate of the node participating in the distributed authentication system This is used to add an electronic signature of the distributed authentication system. However, the secret key of the representative key of the distributed authentication system is distributed and stored by a plurality of representative nodes, and no node on the distributed authentication system can know the secret key of the representative key of the distributed authentication system. On the other hand, the public key of the representative key of the distributed authentication system is disclosed on the distributed authentication system, and any node on the distributed authentication system can be referred to. In this embodiment, a public key cryptosystem is used in which m representative nodes representing a distributed authentication system can set a secret key of a representative key created in cooperation with each other at a random number. As this public key cryptosystem, for example, there is ElGamal cryptosystem.

  Here, the electronic certificate of the node participating in the distributed authentication system is the public key of the personal key created by the m representative nodes representing the distributed authentication system in cooperation with each other and the nodes of the nodes participating in the distributed authentication system. In addition to the information, an electronic signature with the representative key of the distributed authentication system is added to the public key of the personal key and the digest information of the node information. In the present embodiment, a public key cryptosystem is used in which m representative nodes representing the distributed authentication system can set a private key of a private key created in cooperation with each other at a random number. As this public key cryptosystem, for example, there is ElGamal cryptosystem. Here, the digest information indicates summary information of the original information. For example, it is generated by applying a one-way function such as SHA-1 to the original information.

  The mode management unit 2 periodically reads the node information stored in the node information storage unit 8 and confirms whether the number of nodes participating in the distributed authentication system is less than the prescribed number m. When the number of nodes participating in the distributed authentication system is less than the prescribed number m, the node operates in the consensus mode. On the other hand, when the number of nodes participating in the distributed authentication system is the specified number m or more, the node operates in the representative mode. In the representative mode, when designated as a representative node, it operates as a representative node. On the other hand, in the representative mode, when not designated as a representative node, it operates as a general node.

  In addition, the mode management unit 2 in the consensus mode confirms the node list stored in the node information storage unit 8, and if the total number of nodes participating in the distributed authentication system has reached the prescribed number m, the representative mode Migrate to

  When shifting from the consensus mode to the representative mode, all nodes participating in the distributed authentication system at that time, that is, m nodes, become representative nodes. For this purpose, the mode management unit 2 instructs the representative node function unit 4 to generate a representative key for the distributed authentication system. Furthermore, the mode management unit 2 instructs the general node function unit 3 to rejoin the distributed authentication network and obtain an electronic certificate and key issued by the distributed authentication system. Further, the mode management unit 2 instructs the representative node function unit 4 to electronically sign the node list using the secret key of the key. Further, the mode management unit 2 instructs the representative node function unit 4 to add an electronic signature using the representative key of the distributed authentication system to the node list in which the electronic signatures by the m representative nodes have been completed.

  The node list to which the electronic signature by the representative key of the distributed authentication system is added by the above operation is stored in the node information storage unit 8 as a distributed authentication system electronic certificate in a set with the public key of the representative key.

  FIG. 2 shows an example of a distributed authentication system electronic certificate. As shown in the figure, in the distributed authentication system electronic certificate, an electronic signature with a personal key for each representative node is added to a node list including nodes participating in the distributed authentication system and node information (IP address, port number, etc.). An electronic signature using a personal key for each old representative node and an electronic signature using a representative key of the distributed authentication system are added.

  Note that the same operation as in the case of shifting from the consensus mode to the representative mode also operates at the timing when the representative node is updated.

  The general node function unit 3 includes a temporary key generation unit 32 and a participation operation unit 31. When the node is a general node, a function for generating a temporary key and a participation request for participating in the distributed authentication system And a function of transmitting a join request to other nodes already participating in the distributed authentication system.

  Further, the mode management unit 2 distributes the received message to an appropriate function unit.

  The temporary key generation unit 32 generates a temporary key. The generated temporary key is stored in the node information storage unit 8 together with the node information of the own node. The temporary key exists regardless of the key attached to the electronic certificate issued by the distributed authentication system, and the key attached to the electronic certificate issued by the distributed authentication system may be different from the encryption algorithm.

  The participation operation unit 31 transmits a participation request when the own node newly participates in the distributed authentication system. When transmitting a participation request, the public key of the temporary key of the own node is added to the participation request. In addition, the signature adding unit 6 performs an electronic signature on the participation request using the private key of the temporary key of the own node read from the node information storage unit 8. When a participation request is received, the electronic signature is confirmed using the public key of the temporary key added to the participation request. If there is no falsification, a participation response is returned. However, the contents of the participation response differ depending on the mode of the distributed authentication system. When the distributed authentication system is in the consensus mode, the public key of the node's temporary key and the node list are added to the participation response, and the signature adding unit 6 uses the private key of the node's temporary key to generate an electronic signature. After that, the participation response is returned. On the other hand, when the distributed authentication system is in the representative mode, a message indicating that the participation request has been accepted is digitally signed with the private key of the private key of the own node, and the participation response is returned. Further, the participation operation unit 31 reads the node list from the node information storage unit 8, confirms the representative node, and transmits an electronic certificate generation request to a certain representative node. Node information of the node that transmitted the participation request is added to the electronic certificate generation request.

  The representative node function unit 4 includes a random prime number generation unit 41, a representative key generation unit 42, another node personal key generation unit 53, and a representative node nomination / leaving function unit 43, and the node is a representative node In addition, a function to generate a representative key of a distributed authentication system and a distributed authentication system digital certificate in cooperation with other representative nodes, and a participation request or digital certificate generation request from another node are received, and the other nodes A function for generating a personal key and an electronic certificate, a function for leaving the representative node, a function for designating a representative node when the representative node becomes less than the prescribed number m, a representative key of the distributed authentication system, and other functions. And a function of generating a random prime number that is a prime key of the private key of the node.

  The random prime number generation unit 41 receives a request from the representative key generation unit 42 and the other node electronic certificate generation unit 44, generates a random prime number, and generates the generated random prime number from the representative key generation unit 42 and the others. It is passed to the node electronic certificate generation unit 44.

  When the distributed authentication system is in the representative mode and the own node is the representative node, the representative key generating unit 42 receives another instruction from the mode management unit 2 to generate the representative key of the distributed authentication system. A representative key of the distributed authentication system is generated in cooperation with a representative node representing the distributed authentication system. The prime number generated by the random prime number generation unit 41 is used as the prime key prime. The secret key of the representative key is calculated from the prime numbers generated by the m nodes, but is not actually calculated, and only the public key of the representative key is calculated using the m representative nodes and the multi-party protocol. . As a result, only the public key of the representative node is accurately calculated without knowing any node as the secret key of the representative key. The representative key generation unit 42 stores the prime number used for generating the representative key until the node is no longer the representative node.

  In addition, when the distributed authentication system is in the representative mode and the own node is the representative node, the representative key generating unit 42 adds the digital authentication signature of the distributed authentication system from the mode management unit 2 to the node list in which the electronic signatures of the m representative nodes are completed. When an instruction is given to add an electronic signature with a representative key, the electronic signature using the secret key of the representative key of the distributed authentication system is displayed in the node list in cooperation with representative nodes representing the other m distributed authentication systems. Append. As in the case of generating the public key of the distributed authentication system, the m representative nodes cooperate with each other and add an electronic signature to the node list without notifying other nodes of the information that is the prime key.

  When the distributed authentication system is in the representative mode and the own node is the representative node, the other node electronic certificate generation unit 44 receives the electronic certificate generation request, and represents the representative node representing the other m distributed authentication systems. In cooperation with, generate an electronic certificate for the node described in the electronic certificate request. The prime number generated by the random prime number generation unit 41 is used as the prime of the personal key attached to the electronic certificate. The private key of the private key is calculated from the prime numbers generated by the m nodes, but is not actually calculated, and only the public key of the private key is calculated using the m representative nodes and the multi-party protocol. As a result, only the public key of the private key is accurately calculated without knowing any node of the private key of the private key. Further, in cooperation with the representative key generation unit 42, an electronic certificate is generated from the node information of the node and the personal key. The other node electronic certificate generation unit 44 that has completed the above operation transmits the information that is the source of the private key of the personal key, the public key, and the electronic certificate to the node described in the electronic certificate generation request.

  The representative node nomination / leaving function unit 43 reads the node list from the node information storage unit 8 and transmits a representative node leaving request to another representative node when the own node is the representative node and it is desired to leave the representative node. The case where the representative node wants to leave includes, for example, a case where it is desired to leave the distributed authentication system, a case where network resources are insufficient, and a case where an attack from a malicious attacker is received.

  When the representative node nomination / departure function unit 43 receives a representative node leave request when the node is the representative node, the representative node nomination / leave function unit 43 transmits a representative node leave response to the representative node that has transmitted the representative node leave request. Further, the representative node nomination / leaving function unit 43 reads the node list from the node information storage unit 8 and selects an appropriate general node from the state where the representative node is less than the prescribed number m so that the number of representative nodes is m. The representative node designation confirmation message describing the node information of the selected general node is transmitted to all other representative nodes.

  Receiving the representative node designation confirmation message, the representative node designation / departure function unit 43 confirms the node information of the selected general node and returns a representative node designation confirmation response. However, if there is a problem with the selected general node, the nomination can be rejected. Problems include, for example, a response that was slow in the past or an unspecified message being sent. The representative node that has received the representative node nomination confirmation response from all the representative nodes other than itself transmits a representative node nomination request to the selected general node.

  The representative node nomination / departure function unit 43 of the general node that has received the representative node nomination request returns the representative node nomination response to become the representative node. However, the general node that has received the representative node nomination request can also refuse to become the representative node.

  When the representative node nomination / leaving function unit 43 receives the representative node nomination response, the representative node nomination / leaving function unit 43 transmits the node information of the node that newly becomes the representative node to all the representative nodes except the own node. The representative node nomination / leaving function unit 43 repeats the above operation until the number of representative nodes reaches the prescribed number m.

  Further, the representative node nomination / leaving function unit 43 instructs the representative node function unit 4 to electronically sign the node list using the private key of the personal key. Furthermore, the representative node nomination / leaving function unit 43 copies the electronic signature to the node list in which the electronic signature by the node that is the representative node has been completed with respect to the old representative node that was the representative node before the representative key was updated. Instruct them to Further, the representative node nomination / leaving function unit 43 adds a signature with the representative key of the distributed authentication system to the representative node function unit 4 to the node list that has been signed by the m representative nodes and the m old representative nodes. Instruct. The node list to which the electronic signature is added by the above operation is stored in the node information storage unit 8 as a distributed authentication network electronic certificate in combination with the public key of the representative key.

  The common function unit 5 includes a keep alive operation unit 51, an application unit 52, a personal key generation unit 53, and an electronic signature confirmation unit 54. When the node is a general node or a representative node, the keep alive operation is performed. The function of exchanging the node list with other nodes, the function of executing the application using the distributed authentication system, and the private key of the private key from the information that is the source of the private key of the private key received from the m representative nodes And a function of confirming the validity of an electronic signature added to a message received from another node.

  The keep alive operation unit 51 periodically transmits a keep alive message to another node, and further periodically receives a keep alive message from another node to check the connection of the communication path. The keep alive operation unit 51 also attaches the node list read from the node information storage unit 8 to the node list keep alive message, periodically exchanges the node list with other nodes, and updates the node list to a new node list. Thus, the node list is kept up-to-date. For example, a node that has confirmed a node that has newly participated in the distributed authentication system updates the node list, and transmits the latest information to other nodes using a keep alive operation. If there is no response to the keep alive message for a certain period of time, it is determined that the corresponding node has left the distributed authentication system, the node list is updated, and the latest information is transmitted to other nodes using the keep alive operation. However, when it is determined that the representative node has left, the mode management unit 2 is notified that the representative node has left.

  The application unit 52 processes an application that uses the distributed authentication system. Examples of applications include a file exchange application and a telephone application. In the distributed authentication system of this embodiment, there are no restrictions on applications to be used.

  The private key generation unit 53 generates a private key of the private key from m pieces of information that is a source of the private key of the private key received from the m representative nodes. Furthermore, it confirms whether the received public key and private key work effectively. Furthermore, the validity of the received electronic certificate is confirmed.

  The electronic signature confirmation unit 54 confirms an electronic signature added to a certain message and confirms whether the message has been tampered with from the message transmission source. When the electronic signature confirmation unit 54 receives the message, the electronic signature confirmation unit 54 confirms the message transmission source and transmits an electronic certificate issuance request of the message transmission source node to the distributed authentication system. When the electronic certificate of the node that sent the message is obtained, a distributed authentication system electronic certificate issuance request is sent to the distributed authentication system in order to confirm the electronic signature by the representative key of the distributed authentication system added to the electronic certificate. . When the public key of the representative key attached to the distributed authentication system electronic certificate is obtained, the electronic signature attached to the electronic certificate is decrypted with the public key of the representative key, and the validity of the electronic certificate is confirmed. Further, the electronic signature added to the received message is decrypted with the public key of the personal key added to the electronic certificate, and the validity of the message is confirmed.

  In addition, when receiving an electronic certificate issuance request from another node, the electronic signature confirmation unit 54 reads the corresponding electronic certificate from the node information storage unit 8 and returns an electronic certificate issuance response. Further, when receiving the distributed authentication system electronic certificate issuance request from another node, the electronic signature confirmation unit 54 reads the corresponding public key from the node information storage unit 8 and returns a distributed authentication system electronic certificate issuance response. .

  The signature adding unit 6 adds an electronic signature to a message from another functional unit and passes it to the transmitting unit 7. However, the key used for the electronic signature differs depending on the state of the node. When the distributed authentication system is in the consensus mode and when the electronic certificate has not been issued by the distributed authentication system, a temporary key stored in the node information storage unit 8 is used to add an electronic signature to the message. In other cases, a personal key stored in the node information storage unit 8 is used, and an electronic signature is added to the message.

  The transmitting unit 7 receives the message from the signature adding unit 6 and transmits the message to the destination node described in the message.

  The node information storage unit 8 stores the node information, temporary key, electronic certificate, node list, and distributed authentication network electronic certificate of the own node. The electronic certificate can store an electronic certificate of another node in addition to its own electronic certificate. In this case, it is desirable to store the electronic certificate in a distributed manner in each node so that the electronic certificate of all nodes can be shared in the entire distributed authentication system. An example of an algorithm for storing information in a distributed manner is the Chord algorithm.

  Next, the operation of this embodiment will be described in detail with reference to FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7, FIG.

  FIG. 3 shows the operation of the distributed authentication system of this embodiment.

  In FIG. 3, step S-A1 is an initial state. From this initial state, a temporary key is generated (step S-A2), the temporary key and node information are stored (step S-A3), and a participation request is sent to another node that has already participated in the distributed authentication system. Is transmitted (step S-A4). Next, the mode of the distributed authentication system is confirmed (step S-A5). As a result, when the distributed authentication system is in the consensus mode, the process proceeds to step S-AA1. On the other hand, when the distributed authentication system is in the representative mode, the process proceeds to step S-AB1.

  If the distributed authentication system is in consensus mode in step S-A5, the temporary key and node list of the node that transmitted the participation request request are received as a participation request response (step S-AA1), and the node list is updated. To do. Then, the node list is read and it is confirmed whether the temporary keys of all the nodes described in the node list are held (step S-AA2). As a result, when the temporary keys of all the nodes described in the node list are held (Yes), the process proceeds to the consensus mode operation (step S-B1) described later. On the other hand, if the temporary keys of all the nodes described in the node list are not held (No), the process returns to step S-A4, and a participation request request is transmitted to the node that does not hold the temporary keys.

  On the other hand, if the distributed authentication system is in the representative mode in step S-A5, a participation response is received (step S-AB1). Then, the information that is the prime key of the private key and the electronic certificate are received from the m representative nodes (step S-AB2), and the private key is obtained from the information that is the prime key of the received private key. It generates (step S-AB3) and shifts to a later-described general mode operation (step S-C1).

  FIG. 4 shows the consensus mode operation.

  In FIG. 4, step S-B1 is an initial state during the consensus mode operation. From this initial state, a node list is exchanged with a node participating in another distributed authentication system by a keep alive operation (step S-B2). Next, the node list is read, and it is confirmed whether or not the number of nodes participating in the distributed authentication system has reached the specified number m (step S-B3). As a result, when the number of nodes participating in the distributed authentication system has reached the specified number m, the process proceeds to a representative node initial operation (step S-F1) described later. When the number of nodes participating in the distributed authentication system has not reached the specified number m, the process proceeds to the initial state (step S-B1).

  FIG. 5 shows a general node operation.

  In FIG. 5, step S-C1 is an initial state when the general node operates. From this initial state, the node list is read, a keep alive message with the node list added is transmitted to the other nodes (step S-CA1), and the process returns to the initial state (step S-C1).

  Next, in an initial state (step S-C1), a keep alive message to which a node list is added is received from another node (step S-CB2). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, the node list added to the received keep alive message is compared with the node list stored in the own node and updated to the latest information (step S-CB2). The node list is read, and it is confirmed whether or not the number of nodes participating in the distributed authentication system has reached the specified number m (step S-CB3). As a result, when the number of nodes participating in the distributed authentication system has reached the specified number m (Yes), the process proceeds to the initial state (step S-C1). On the other hand, when the number of nodes participating in the distributed authentication system has not reached the specified number m (No), the process proceeds to the above-mentioned consensus mode operation (step S-B1).

  Next, in the initial state (step S-C1), a participation request is received (step S-CC1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, a participation response is transmitted to the node that has transmitted the participation request (step S-CC2), and an electronic certificate creation request is transmitted to an arbitrary representative node among the m representative nodes (step S). -CC3). This electronic certificate creation request includes node information of the node that has transmitted the participation request in step S-CB1.

  Next, in the initial state (step S-C1), a representative node nomination request is received (step S-CD1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, it is confirmed whether or not to become a representative node is rejected (step S-CD2). As a result, if there is no problem even if it becomes the representative node (No), in order to become the representative node, a representative node nomination response is transmitted to the node that has transmitted the representative node nomination request in step S-CC1 (step S). -CD3-1), and shifts to a representative node initial operation (step S-F1) described later. On the other hand, when refusing to become a representative node (Yes), in order to refuse to become a representative node, information on representative node refusal is sent to the node that sent the representative node nomination request in step S-CD1. In addition, a representative node nomination response is transmitted (step S-CD3-2), and the process proceeds to the initial state (step S-C1) when the general node is operating.

  Next, in the initial state (step S-C1), an electronic certificate issuance request is received (step S-CE1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step. Next, an electronic certificate issuance response added with the electronic certificate of the own node is transmitted to the node that has transmitted the electronic certificate issuance request in step S-CE1 (step S-CE2).

  FIG. 6 shows the representative node operation.

  In FIG. 6, step S-D1 is an initial state when the representative node operates. From this initial state, the node list is read, a keep alive message with the node list added is transmitted to the other nodes (step S-DA1), and the process returns to the initial state (step S-D1).

  Next, in an initial state (step S-D1), a keep alive message with the node list added is received from another node (step S-DB1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, the node list added to the keep alive message received in step S-DB1 is compared with the node list stored in the own node and updated to the latest information (step S-DB2). Then, the node list is read, and it is confirmed whether or not the number of nodes participating in the distributed authentication system has reached the prescribed number m (step S-DB3).

  As a result, when the number of nodes participating in the distributed authentication system has reached the prescribed number m (Yes), the node list is read to check whether the representative node has left (step S-DB4). When it has left | separated (Yes), it transfers to the below-mentioned representative node update operation | movement (step S-G1). On the other hand, if the representative node has not left, the process proceeds to the initial state (step S-D1).

  On the other hand, when the number of nodes participating in the distributed authentication system has not reached the specified number m in step S-DB3 (No), the process proceeds to the above-mentioned consensus mode operation (step S-B1).

  Next, when it is desired to leave the representative node in the initial state (step S-D1), a representative node leave request is transmitted to other representative nodes (step S-DC1). Then, the representative node leaving response is received (step S-DC2). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to the next step. The process proceeds to a later-described representative mode leaving operation (step S-H1).

  Next, in the initial state (step S-D1), a participation request is received (step S-DD1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later, and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, a participation response is transmitted to the node that has transmitted the participation request (step S-DD2), and a random prime number that is information serving as the prime key of the private key of the node that has transmitted the participation request is generated ( Step S-DD3). Then, the m representative nodes cooperate with each other to generate the public key of the private key of the node that has transmitted the participation request (step S-DD4), and the m representative nodes cooperate with each other to send the participation request. An electronic certificate of the transmitting node is generated (step S-DD5).

  Next, information that is a source of the private key of the private key of the node that has transmitted the participation request generated in step S-DD3, and the public key of the private key of the node that has transmitted the participation request generated in step S-DD4 The electronic certificate of the node that has transmitted the participation request generated in step S-DD5 is transmitted to the node that has transmitted the participation request (step S-DD6), and the process proceeds to the initial state (step S-D1). .

  Next, in the initial state (step S-D1), an electronic certificate generation request is received (step S-DE1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to step S-DD3. The same process is performed.

  Next, in the initial state (step S-D1), a representative node leaving request is received (step S-DF1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to the next step. A representative node leaving response is transmitted (step S-DF2), and the process proceeds to a later-described representative node update operation (step S-G1).

  Next, in the initial state (step S-D1), a representative node nomination confirmation message is received (step S-DG1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to the next step. A representative node nomination confirmation response is transmitted (step S-DG2), and the process proceeds to a later-described representative node initial operation (step S-F1). When refusing to make the node described in the representative node designation confirmation message received in step S-DG1 a representative node, the information is added to the representative node designation confirmation response.

  Next, in the initial state (step S-D1), an electronic certificate issuance request is received (step S-DH1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to the next step. An electronic certificate issuance response added with the electronic certificate of the own node is transmitted to the node that has transmitted the electronic certificate issuance request in step S-DH1 (step S-DH2), and the initial state (step S-D1). Migrate to

  Next, in the initial state (step S-D1), a distributed authentication system electronic certificate issuance request is received (step S-DI1). At this time, when the validity of the received message is confirmed, the process proceeds to a signature confirmation operation (step S-E1) described later. When the validity of the received message is confirmed, the process proceeds to the next step. In step S-DI1, a distributed authentication system electronic certificate issuance response to which the distributed authentication system electronic certificate is added is transmitted to the node that has transmitted the distributed authentication system electronic certificate issuance request (step S-DI2). The process proceeds to (Step S-D1).

  FIG. 7 shows the signature confirmation operation.

  In FIG. 7, step S-E1 is an initial state of the signature verification operation. From this initial state, an electronic certificate issuance request of the message transmission source node is transmitted to the node that transmitted the message (step S-E3). Alternatively, when the electronic certificate of the node that sent the message is distributed and stored on the distributed authentication system, an electronic certificate issuance request is transmitted to an appropriate node. Note that this step may be skipped if the electronic certificate of the node that sent the message has already been held.

  Next, an electronic certificate issuance response is received (step S-E4). At this time, when the validity of the received message is confirmed, the process proceeds to the initial state (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step. If step S-E3 has been skipped, this step is also skipped.

  Next, a distributed authentication system electronic certificate issuance request is transmitted to the representative node (step S-E5). This step may be skipped if the distributed authentication system electronic certificate has already been held.

  Next, the distributed authentication system electronic certificate issuance response is received (step S-E6). At this time, when the validity of the received message is confirmed, the process proceeds to the initial state (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step. If step S-E5 has been skipped, this step is also skipped.

  Next, using the public key of the representative key attached to the distributed authentication system electronic certificate, the electronic signature attached to the electronic certificate is decrypted with the public key of the representative key, and the validity of the electronic certificate is confirmed. (Step S-E7). Further, the electronic signature added to the received message is decrypted with the public key of the personal key added to the electronic certificate, and the validity of the message is confirmed.

  FIG. 8 shows the representative node initial operation.

  In FIG. 8, step S-F1 is an initial state during the initial operation of the representative node. From this initial state, a random prime number serving as information that is a prime secret key of the representative key of the distributed authentication system is generated (step S-F2), and the m representative nodes cooperate with each other to represent the representative key of the distributed authentication system. Is generated (step S-F3). Then, an electronic signature is applied to the node list at this time using the private key of the private key (step S-F4), and the node list with the electronic signature is transmitted to the other representative nodes (step S-F5). ).

  Next, a node list is received from another representative node (step S-F6). At this time, when the validity of the received message is confirmed, the process proceeds to the above-described signature confirmation operation (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, it is confirmed whether the electronic signatures of all the representative nodes are added to the node list received in step S-F6 (step S-F7). As a result, if the electronic signatures of all the representative nodes have been added to the node list received in step S-F6 (Yes), the process proceeds to step S-F8. On the other hand, when the electronic signatures of all the representative nodes are not added to the node list received in step S-F6 (No), the process proceeds to the above-described step S-F4, and the same processing is repeatedly executed.

  In step S-F7, when the electronic signatures of all the representative nodes are added to the node list received in step S-F6, the node list in which the electronic signatures of all the representative nodes are completed is set as the remaining old representative nodes. The node list is transmitted (step S-F8), and the node list to which the electronic signature by the remaining old representative node is added is received (step S-F9). At this time, when the validity of the received message is confirmed, the process proceeds to the above-described signature confirmation operation (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, it is confirmed whether the electronic signature by all the remaining old representative nodes is added to the node list received in step S-F9 (step S-F10). As a result, if the electronic signatures of all the old representative nodes are added to the node list received in step S-F9 (Yes), the m representative nodes cooperate with each other to create a distributed authentication system electronic certificate. (Step S-F11), the process proceeds to the above-described representative node operation (Step S-D1). When the electronic signatures of all the representative nodes are not added to the node list received in step S-F9 (No), the process proceeds to the above-described step S-F8, and the same processing is repeatedly executed.

  FIG. 9 shows the representative node update operation.

  In FIG. 9, step S-G1 is an initial state during the representative node update operation. From this initial state, a node that newly becomes a representative node is selected (step S-G2), and a representative node designation confirmation message is transmitted to other representative nodes (step S-G3).

  Next, a representative node nomination confirmation response is received (step S-G4). At this time, when the validity of the received message is confirmed, the process proceeds to the above-described signature confirmation operation (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, it is confirmed whether or not a message rejecting the node selected in step S-G2 is added to the representative node nomination confirmation response received in step S-G4 (step S-G5). As a result, when the message for rejecting the node selected in step S-G2 is added to the representative node nomination confirmation response received in step S-G4 (Yes), the process proceeds to the initial state (step S-G1). .

  On the other hand, when the message for rejecting the node selected in step S-G2 is not added to the representative node nomination confirmation response received in step S-G4 (No), for the node selected in step S-G2, A representative node nomination request is transmitted (step S-G6).

  Next, a representative node nomination response is received from the node selected in step S-G2 (step S-G7). At this time, when the validity of the received message is confirmed, the process proceeds to the above-described signature confirmation operation (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, it is confirmed whether or not a message refusing to become a representative node is added to the representative node nomination response received in step S-G7 (step S-G8). As a result, when a message refusing to become a representative node is added to the representative node nomination response received in step S-G7 (Yes), the process proceeds to the initial state (step S-G1).

  On the other hand, if a message refusing to become a representative node has not been added to the representative node nomination response received in step S-G7 (No), it is confirmed whether the number of representative nodes has reached the specified number m ( Step S-G9). As a result, when the number of representative nodes has reached the specified number m (Yes), the process proceeds to the above-described representative node initial operation (step S-F1). On the other hand, if the number of representative nodes has not reached the specified number m (No), the process proceeds to the initial state (step S-G1).

  FIG. 10 shows the representative node leaving operation.

  In FIG. 10, step S-H1 is an initial state during the representative node leaving operation. In this state, the representative node is recognized as the old representative node. Next, the node list to which the electronic signatures of all the representative nodes are added is received from the representative node (step S-H2). At this time, when the validity of the received message is confirmed, the process proceeds to the above-described signature confirmation operation (step S-E1), and when the validity of the received message is confirmed, the process proceeds to the next step.

  Next, an electronic signature is added to the node list received in step S-G2 (step S-H3), and the node list to which the electronic signatures of all representative nodes are added in step S-G2 On the other hand, the node list to which the electronic signature is added in step S-G3 is transmitted (step S-H4).

  Next, the effect of the present embodiment will be described.

  In this embodiment, a predetermined number m of nodes participating in the distributed authentication system become representative nodes, issue of the representative key of the distributed authentication system and the distributed authentication system electronic certificate, and the nodes participating in the distributed authentication system. The issuance of personal keys and electronic certificates is realized by the m representative nodes cooperating with each other, and the representative nodes can be nominated and withdrawn flexibly to attack against attacks from malicious attackers. Even if the target can be distributed and attacked, the authentication service can be continued without losing the function as the distributed authentication system by changing the representative node one after another.

  In this embodiment, a predetermined number of m nodes among the nodes participating in the distributed authentication system become representative nodes, issue the representative key of the distributed authentication system and the distributed authentication system electronic certificate, and participate in the distributed authentication system. The issuance of a node's personal key and electronic certificate is realized by the m representative nodes cooperating with each other, and there is a certificate authority at a specific location by making the representative node's nomination and withdrawal flexible. It is possible to provide an authentication service having the same level of security as the case.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

  Referring to FIG. 11, the present embodiment is similar to the first embodiment in that the receiving unit 1, the mode management unit 2, the general node function unit 3, the representative node function unit 4, the common function unit 5, A node information storage unit 8, a signature addition unit 6, and a transmission unit 7.

  Furthermore, the present embodiment has a distributed authentication system program.

  The distributed authentication system program includes a receiving unit 1, a mode management unit 2, a general node function unit 3, a representative node function unit 4, a common function unit 5, a node information storage unit 8, and a signature addition unit 6. , The transmission unit 7, the reception unit 1, the mode management unit 2, the general node function unit 3, the representative node function unit 4, the common function unit 5, the node information storage unit 8, and the signature addition unit 6 and the operation of the transmitter 7 is controlled. The receiving unit 1, the mode management unit 2, the general node function unit 3, the representative node function unit 4, the common function unit 5, the node information storage unit 8, the signature addition unit 6, and the transmission unit 7 are distributed. The same processing as that performed by the distributed authentication system in the first embodiment is executed under the control of the authentication system program.

  Next, the effect of the present embodiment will be described.

  In this embodiment, in order to obtain the same effect as that of the first embodiment, the computer can be operated as a distributed authentication system by using the distributed authentication system program.

  As mentioned above, although the Example of this invention was described in detail, this invention is not limited to the above-mentioned Example illustrated typically, and those skilled in the art will be based on description content of a claim. The present invention can be modified and changed into various modes without departing from the gist of the present invention. These modified examples and modified examples also belong to the scope of the right of the present invention.

  For example, when realizing at least a part of the functions of each unit constituting the above distributed authentication system using a program code, the program code and a recording medium for recording the program code are included in the scope of the present invention. In this case, when the above functions are realized in cooperation with other software such as an operating system, those program codes are also included.

It is a block diagram which shows the whole structure of the distributed authentication system which concerns on 1st Example of this invention. It is a figure which shows an example of the distributed authentication system electronic certificate used with the distributed authentication system which concerns on 1st Example of this invention. It is a flowchart which shows operation | movement of the distributed authentication system which concerns on 1st Example of this invention. It is a flowchart which shows the consensus mode operation | movement of the distributed authentication system which concerns on 1st Example of this invention. It is a flowchart which shows the general node operation | movement of the distributed authentication system based on 1st Example of this invention. It is a flowchart which shows the representation node operation | movement of the distributed authentication system based on 1st Example of this invention. It is a flowchart which shows the signature verification operation | movement of the distributed authentication system based on 1st Example of this invention. It is a flowchart which shows the representative node initial stage operation | movement of the distributed authentication system based on 1st Example of this invention. It is a flowchart which shows the representative node update operation | movement of the distributed authentication system which concerns on 1st Example of this invention. 3 is a flowchart showing a representative node leaving operation of the distributed authentication system according to the first exemplary embodiment of the present invention. It is a block diagram which shows the whole structure of the distributed authentication system which concerns on 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception part 2 Mode management part 3 General node function part 4 Representative node function part 5 Common function part 6 Signature addition part 7 Transmission part 9 Distributed authentication system program 31 Participation operation part 32 Temporary key generation part 41 Random prime number generation part 42 Representative Key generation unit 43 Representative node nomination / leaving function unit 44 Other node electronic certificate generation unit 51 keep alive operation unit 52 application unit 53 personal key generation unit 54 electronic signature confirmation unit

Claims (41)

A distributed authentication system composed of one or more nodes,
A predetermined number of nodes among the nodes participating in the distributed authentication system are representative nodes representing the distributed authentication system,
When the representative nodes cooperate with each other, a representative key used in an electronic signature of the distributed authentication system, a distributed authentication system electronic certificate, a personal key used in an electronic signature of a node participating in the distributed authentication system, A distributed authentication system, which issues an electronic certificate of a node participating in the distributed authentication system. The distributed authentication system according to claim 1,
The nodes constituting the distributed authentication system are:
A receiver that receives data sent from another node;
A node information storage unit for storing a node list including information on nodes constituting the distributed authentication system in an updatable manner;
Based on the node list, as a mode of the distributed authentication system, a consensus mode when the total number of nodes participating in the distributed authentication system is less than a predetermined number, and a total number of nodes participating in the distributed authentication system being a predetermined number or more A mode management unit for managing the representative mode at the time of
In the case of the representative mode, a representative node function unit that performs an operation at the time of the representative node;
In the case of the representative mode, a general node function unit that performs an operation at a general node other than the representative node;
A common function unit that performs operations common to the consensus mode and the representative mode;
A signature adding unit that adds an electronic signature to data to the other node passed from the representative node function unit, the general node function unit, and the common function unit;
A distributed authentication system, comprising: a transmission unit configured to transmit data to which the electronic signature is added to the other node. In the distributed authentication system according to claim 2,
The general node function unit is:
A temporary key generation unit having a function of generating a temporary key when the node is the general node;
A distributed authentication system comprising: a participation operation unit having a function of transmitting a participation request for participating in the distributed authentication system to another node already participating in the distributed authentication system. In the distributed authentication system according to claim 2,
The representative node function unit includes:
When the node is the representative node, a representative key generation unit that generates the representative key and the distributed authentication system electronic certificate in cooperation with other representative nodes;
An other node electronic certificate generation unit that receives a participation request or an electronic certificate generation request from another node, and generates a personal key of the other node and its electronic certificate;
A representative node nomination / leaving function unit having a function of nominating the representative node when the number of representative nodes is less than a specified number, and a function of leaving the representative node;
A distributed authentication system, comprising: a random prime number generation unit that generates a random prime number that is a prime key of the representative key and a private key of the other node. In the distributed authentication system according to claim 2,
The common function unit is:
A keep alive operation unit for exchanging the node list with another node by a keep alive operation when the node is the general node or the representative node;
An application unit that implements an application that uses the distributed authentication system;
A personal key generating unit that generates a private key of the personal key from information that is a prime key of the private key received from the specified number of representative nodes;
A distributed authentication system comprising: an electronic signature confirmation unit for confirming validity of an electronic signature added to a message received from the other node. In the distributed authentication system according to claim 2,
The distributed authentication system, wherein the reception unit sends a received message to the mode management unit. In the distributed authentication system according to claim 2,
The mode management unit
A function of reading a node list stored in the node information storage unit;
A function of confirming the number of nodes participating in the distributed authentication system;
A function of confirming the mode of the distributed authentication system;
A function of managing whether the own node is the representative node or the general node;
A function of periodically reading out node information stored in the node information storage unit and confirming whether the number of nodes participating in the distributed authentication system is less than the predetermined number or not,
When the number of nodes participating in the distributed authentication system is less than the predetermined number, the function of operating the own node in the consensus mode;
When the number of nodes participating in the distributed authentication system is equal to or greater than the predetermined number, a function of operating the own node in the representative mode;
When designated as the representative node, the function of operating the own node as the representative node;
When not designated as the representative node, the function of operating the own node as the general node;
In the consensus mode, the node list stored in the node information storage unit is confirmed, and when the total number of nodes participating in the distributed authentication system has reached the predetermined number, the own node is changed to the representative mode. With the ability to transition to
A function to instruct the representative node function unit to generate a representative key of the distributed authentication system;
A function to instruct the general node function unit to rejoin the distributed authentication network and obtain an electronic certificate and key issued by the distributed authentication system;
A function of instructing the representative node function unit to electronically sign the node list using a secret key of the key;
A function to instruct the representative node function unit to add an electronic signature by the representative key to the node list in which the electronic signature by the predetermined number of representative nodes has been completed;
A distributed authentication system comprising: a function of distributing a received message to an appropriate function unit; The distributed authentication system according to claim 1,
The representative node is
A function of cooperating with other representative nodes to generate the representative key and the distributed authentication system electronic certificate;
A function of receiving a participation request or an electronic certificate generation request from another node, and generating the personal key and the electronic certificate of the other node;
A function of leaving the representative node;
A function of nominating the representative node when the representative node is less than the predetermined number;
A function of generating a random prime that is a prime of a secret key of the representative key and the private key of the other node;
A function of exchanging the node list with the other node by the keep-alive operation;
A function for executing an application using the distributed authentication system;
A function of generating a private key of the personal key from information that is a source of a private key of the private key received from the predetermined number of representative nodes;
A distributed authentication system, comprising: a function of confirming validity of an electronic signature added to a message received from the other node. In the distributed authentication system according to claim 2,
The node list includes node information of all nodes participating in the distributed authentication system and representative node information. The distributed authentication system according to claim 9, wherein
The distributed authentication system, wherein the node information includes a node ID, a node IP address, a port number, representative node information, and old representative node information. The distributed authentication system according to claim 9, wherein
The distributed authentication system, wherein the representative node information includes information indicating which node the representative node is. The distributed authentication system according to claim 9, wherein
The old representative node information includes information indicating which node the representative node was in the past. In the distributed authentication system according to claim 3,
The temporary key is not a key issued by the distributed authentication system, but a key generated by each node. When newly joining the distributed authentication system and in the consensus mode, the temporary key is sent to another node. A distributed authentication system, which is used for an electronic signature added to all the messages. The distributed authentication system according to claim 1,
The representative key consists of a secret key and a public key of a public key cryptosystem,
The distributed authentication system according to claim 1, wherein the personal key comprises a public key cryptosystem private key and a personal key. The distributed authentication system according to claim 1,
The representative key is used when an electronic signature of the distributed authentication system is added to a node list and an electronic certificate of a node participating in the distributed authentication system,
The secret key of the representative key is distributed and stored in a plurality of representative nodes so that no node on the distributed authentication system can know.
The distributed authentication system, wherein the public key of the representative key is disclosed on the distributed authentication system so that any node on the distributed authentication system can be referred to. The distributed authentication system according to claim 1,
The electronic certificate of the node participating in the distributed authentication system includes the public key of the personal key and the information of the node participating in the distributed authentication system, as well as the digest information of the public key of the personal key and the information of the node. A distributed authentication system, wherein an electronic signature using the representative key is added to the system. The distributed authentication system according to claim 16, wherein
The distributed authentication system is characterized in that the digest information is summary information of the original information and is generated by applying a one-way function to the original information. In the distributed authentication system according to claim 3,
The participation operation unit
A function of transmitting a participation request to which the public key of the temporary key is added together with an electronic signature using a private key of the temporary key of the own node when the own node newly participates in the distributed authentication system;
A function of confirming the electronic signature using the public key of the temporary key added to the participation request when the participation request is received from another node, and transmitting a participation response when there is no falsification;
A function of adding the public key of the temporary key of the own node and a node list to the participation response when the distributed authentication system is in the consensus mode, and transmitting the electronic signature together with the private key of the temporary key of the own node; ,
When the distributed authentication system is in a representative mode, a message to the effect that the participation request has been accepted is added to the participation response, and the electronic signature is sent together with the private key of the private key of the own node;
A function of reading a node list from the node information storage unit, confirming the representative node, and transmitting a digital certificate generation request with node information of the node that has transmitted the participation request to a certain representative node; A distributed authentication system comprising: In the distributed authentication system according to claim 3,
The distributed authentication system, wherein the temporary key generation unit has a function of generating the temporary key and a function of storing the generated temporary key in the node information storage unit together with node information of the own node. The distributed authentication system according to claim 4,
The random prime number generation unit
A function of receiving a request from the representative key generation unit and the other node electronic certificate generation unit, and generating a random prime number;
A distributed authentication system comprising: a function of passing the generated random prime number to the representative key generation unit and the other node electronic certificate generation unit. The distributed authentication system according to claim 4,
The representative key generation unit
When the distributed authentication system receives the instruction to generate the representative key from the mode management unit when the distributed authentication system is the representative mode and the own node is the representative node, the random prime number cooperates with another representative node. A function for generating a public key of the representative key using a multi-party protocol without informing other nodes of information that is a prime of the public key of the representative key, using a prime number generated by the generation unit;
A function of storing a prime number used to generate the representative key until the own node is no longer the representative node;
When the distributed authentication system is the representative mode and the own node is the representative node, the electronic signature by the representative key is added from the mode management unit to the node list in which the electronic signature by the predetermined number of representative nodes is completed. If the instruction is received, the function of adding an electronic signature using the secret key of the representative key to the node list in cooperation with another representative node without notifying other nodes of the information that is the prime key element. A distributed authentication system comprising: The distributed authentication system according to claim 4,
The representative node nomination / leaving function unit is
When the own node is the representative node and wants to leave the representative node, the node information is read from the node information storage unit and a representative node leave request is transmitted to another representative node;
When the local node is the representative node and receives the representative node leave request, a function of transmitting a representative node leave response to the representative node that has transmitted the representative node leave request;
From the state where the representative node is less than the predetermined number, in order to set the representative node to the predetermined number, a function of reading a node list from the node information storage unit and selecting an appropriate general node;
A function of transmitting a representative node nomination confirmation message describing node information of the selected general node to all other representative nodes;
A function of confirming the node information of the selected general node when the representative node nomination confirmation message is received and returning a representative node nomination confirmation response including availability information;
When a representative node nomination confirmation response is received from all the representative nodes except the own node, a function of transmitting a representative node nomination request to the selected general node;
A function of returning a representative node nomination response including availability information when the own node is the general node and the node representative node nomination request is received;
When receiving the representative node nomination response, the function of transmitting the node information of the node that will be the new representative node to all the representative nodes except the own node;
A function of instructing the representative node function unit to electronically sign a node list using a private key of the personal key;
A function for instructing the old representative node, which was the representative node before updating the representative key, to digitally sign a node list in which the electronic signature by the node that is currently the representative node has ended;
A function of instructing the representative node function unit to add an electronic signature by the representative key to a node list in which the electronic signature by the predetermined number of representative nodes and the predetermined number of old representative nodes has been completed;
A distributed authentication system comprising: a function that stores the node list to which the electronic signature is added and the public key of the representative key as a set as the distributed authentication network electronic certificate in the node information storage unit; . The distributed authentication system according to claim 22,
The representative node nomination / leaving function unit has a function of repeating each function until the number of representative nodes reaches the specified number. The distributed authentication system according to claim 4,
The other node electronic certificate generation unit
When the distributed authentication system receives the electronic certificate generation request when the representative mode is the representative mode and the own node is the representative node, the prime number generated by the random prime number generation unit is primed in cooperation with another representative node. A function for generating a personal key of a node described in an electronic certificate request using a multi-party protocol without notifying other nodes of information that is a source of a private key attached to the electronic certificate;
A function of generating an electronic certificate from node information of the node and the personal key in cooperation with the representative key generation unit;
A distributed authentication system comprising: information that is a source of a private key of the personal key, a public key, and a function of transmitting the electronic certificate to a node described in an electronic certificate generation request. The distributed authentication system according to claim 5,
The keep-alive operation unit
A function to periodically send keep-alive messages to other nodes;
A function of periodically checking the connection of the communication path by receiving the keep-alive message from another node;
A function of comparing the node list added to the keep-alive message with the node list read from the node information storage unit, and updating the node list to the latest information;
When there is no response to the keep alive message for a certain period, the node determines that it has left the distributed authentication system, updates the node list, and transmits the latest information to other nodes using the keep alive operation When,
A distributed authentication system comprising: a function of transmitting, when it is determined that the representative node has left, to the node management unit that the representative node has left. The distributed authentication system according to claim 5,
The distributed authentication system, wherein the application unit has a function of processing an application that uses the distributed authentication system. The distributed authentication system according to claim 5,
The personal key generator is
A function of generating a private key of the personal key from a predetermined number of information that is a prime of a private key of the personal key received from the predetermined number of representative nodes;
A function for confirming whether the received public key and private key of the personal key are valid, and
And a function of confirming the validity of the received electronic certificate. The distributed authentication system according to claim 5,
The electronic signature verification unit
A function of confirming a message transmission source when a message is received, and transmitting an electronic certificate issuance request of a message transmission source node to the distributed authentication system;
When the electronic certificate of the node that sent the message is obtained, a distributed authentication system electronic certificate issuance request is sent to the distributed authentication system in order to confirm the electronic signature with the representative key added to the electronic certificate. Function to
When the public key of the representative key attached to the distributed authentication system electronic certificate is obtained, the electronic signature attached to the electronic certificate is decrypted with the public key of the representative key, and the electronic certificate A function to check the validity of
A function of decrypting the electronic signature added to the received message with the public key of the personal key added to the electronic certificate and confirming the validity of the message;
A function of reading out a corresponding electronic certificate from the node information storage unit when an electronic certificate issuance request is received from another node, and returning an electronic certificate issuance response;
A function of reading a corresponding public key from the node information storage unit and transmitting a distributed authentication system electronic certificate issuance response when the distributed authentication system electronic certificate issuance request is received from another node. Distributed authentication system. In the distributed authentication system according to claim 2,
The signature adding unit
When the distributed authentication system is in the consensus mode, a temporary key stored in the node information storage unit is used, and a message from the general node function unit, the representative node function unit, and the common function unit is digitally signed With the function of adding
Using the temporary key stored in the node information storage unit when the electronic certificate has not been issued by the distributed authentication system, the general node function unit, the representative node function unit, and the common function A function to add an electronic signature to a message from the department,
When the distributed authentication system is not in the consensus mode but when the electronic certificate is issued by the distributed authentication system, the personal key stored in the node information storage unit is used, and the general key is used. A distributed authentication system, comprising: a node function unit, a representative node function unit, and a function of adding an electronic signature to a message from the common function unit. In the distributed authentication system according to claim 2,
The distributed authentication system has a function of receiving a message from the signature adding unit and transmitting the message to a destination node described in the message. In the distributed authentication system according to claim 2,
The node information storage unit has a function of storing node information of a local node, a temporary key, the electronic certificate, the node list, and the distributed authentication network electronic certificate. A distributed authentication system including one or a plurality of nodes, and a predetermined number of nodes among the nodes participating in the distributed authentication system are representative nodes representing the distributed authentication system, and the representative nodes cooperate with each other. A representative key used in the electronic signature of the distributed authentication system, a distributed authentication system electronic certificate, a personal key used in an electronic signature of a node participating in the distributed authentication system, and a node participating in the distributed authentication system. A distributed authentication method for a distributed authentication system that issues an electronic certificate,
(A) starting participation in the distributed authentication system;
(B) when the total number of nodes participating in the distributed authentication system is less than a predetermined number, performing a consensus mode operation;
(C) when the total number of nodes participating in the distributed authentication system is equal to or greater than a predetermined number, the operation of the general node other than the representative node as the operation of the representative mode;
(D) performing the operation at the time of the representative node as the operation of the representative mode;
(E) performing an operation for confirming an electronic signature of a message received from another node;
(F) performing an initial operation of the representative node;
(G) performing an operation when updating the representative node;
(H) A step of performing an operation when leaving the representative node. The distributed authentication method according to claim 32, wherein
(A) starting the participation in the distributed authentication system includes:
(A1) an initial state step;
(A2) generating a temporary key;
(A3) storing the temporary key and node information;
(A4) transmitting a participation request to another node already participating in the distributed authentication system;
(A5) confirming the mode of the distributed authentication system;
(A6) receiving a temporary key and a node list of the node that transmitted the participation request as a participation request response, and updating the node list;
(A7) reading the node list and confirming whether the temporary keys of all the nodes described in the node list are held;
(A8) receiving a participation response;
(A9) receiving information that is a source of a private key of a private key from a predetermined number of representative nodes and an electronic certificate;
(A10) A distributed authentication method comprising: generating a personal key from information that is a source of a private key of the received personal key. The distributed authentication method according to claim 32, wherein
The step (B) of performing the consensus mode operation is as follows:
(B1) an initial state step during operation of the consensus mode;
(B2) exchanging a node list with a node participating in another distributed authentication system by a keep alive operation;
(B3) A step of reading the node list and confirming whether or not the number of nodes participating in the distributed authentication system has reached a predetermined number. The distributed authentication method according to claim 32, wherein
The step of performing the operation when the (C) general node is performed,
(C1) an initial state step of the general node operation;
(C2) reading the node list and transmitting a keep alive message with the node list added to other nodes;
(C3) receiving a keep-alive message with the node list added from another node;
(C4) comparing the node list added to the received keep-alive message with the node list stored in the own node and updating to the latest information;
(C5) reading the node list and confirming whether the number of nodes participating in the distributed authentication system has reached a predetermined number;
(C6) receiving a participation request;
(C7) transmitting a participation response to the node that has transmitted the participation request;
(C8) transmitting an electronic certificate creation request to an arbitrary representative node among the predetermined number of representative nodes;
(C9) receiving a representative node nomination request;
(C10) selecting whether to become the representative node;
(C11) transmitting a representative node nomination response to the node that has transmitted the representative node nomination request to become the representative node;
(C12) adding a representative node rejection information and transmitting a representative node nomination response to the node that has transmitted the representative node nomination request in order to refuse to become a representative node;
(C13) receiving an electronic certificate issuance request;
(C14) A distributed authentication method comprising: a step of transmitting an electronic certificate issuance response to which the electronic certificate of the own node is added to a node that has transmitted the electronic certificate issuance request. The distributed authentication method according to claim 32, wherein
The step of performing the operation when the (D) representative node is
(D1) an initial state step during operation of the representative node;
(D2) reading the node list and transmitting a keep-alive message with the node list added to the other nodes;
(D3) receiving a keep-alive message with the node list added from another node;
(D4) comparing the node list added to the received keep-alive message with the node list stored in the own node and updating to the latest information;
(D5) reading the node list and confirming whether the number of nodes participating in the distributed authentication system has reached a predetermined number;
(D6) reading the node list and confirming whether the representative node has left;
(D7) If it is desired to leave the representative node, a step of sending a representative node leave request to another representative node;
(D8) receiving a representative node leaving response;
(D9) receiving a participation request;
(D10) transmitting a participation response to the node that has transmitted the participation request;
(D11) generating a random prime number that is information serving as a prime key of the private key of the private key of the node that has transmitted the participation request;
(D12) generating a public key of a personal key of a node that has cooperated with each other among the predetermined number of representative nodes and has transmitted a participation request;
(D13) generating a digital certificate of the node that has transmitted the participation request in cooperation with each other between the predetermined number of representative nodes;
(D14) transmitting to the node that has transmitted the participation request, information that is a source of the private key of the personal key, a public key of the personal key, and the electronic certificate;
(D15) receiving an electronic certificate generation request;
(D16) receiving a representative node leaving request;
(D17) transmitting a representative node leaving response;
(D18) receiving a representative node nomination confirmation message;
(D19) transmitting a representative node nomination confirmation response;
(D20) receiving an electronic certificate issuance request;
(D21) transmitting an electronic certificate issuance response to which the electronic certificate of the own node is added to the node that has transmitted the electronic certificate issuance request;
(D22) receiving the distributed authentication system electronic certificate issuance request;
(D23) transmitting a distributed authentication system electronic certificate issuance response added with the distributed authentication system electronic certificate to the node that has transmitted the distributed authentication system electronic certificate issuance request. Distributed authentication method. The distributed authentication method according to claim 32, wherein
(E) The step of performing an operation when confirming the electronic signature of the received message is as follows:
(E1) an initial state step of signature verification operation;
(E2) transmitting an electronic certificate issuance request of a message transmission source node;
(E3) receiving an electronic certificate issuance response;
(E4) transmitting a distributed authentication system electronic certificate issuance request to the representative node;
(E5) receiving a distributed authentication system electronic certificate issuance response;
(E6) The public key of the representative key added to the distributed authentication system electronic certificate is used to decrypt the electronic signature added to the electronic certificate with the public key of the representative key, and the validity of the electronic certificate And decrypting the electronic signature attached to the received message with the public key of the personal key attached to the electronic certificate, and confirming the validity of the message. A distributed authentication method characterized by the above. The distributed authentication method according to claim 32, wherein
(F) performing the initial operation of the representative node includes:
(F1) an initial state step during the initial operation of the representative node;
(F2) generating a random prime number that is information that is a prime key private key of the distributed authentication system;
(F3) generating a public key of a representative key of the distributed authentication system in cooperation with each other between a predetermined number of representative nodes;
(F4) electronically signing the node list at this time using the private key of the personal key;
(F5) transmitting an electronically signed node list to another representative node;
(F6) receiving a node list from another representative node;
(F7) confirming whether the electronic signatures of all the representative nodes are added to the received node list;
(F8) transmitting a node list in which electronic signatures by all the representative nodes are completed to the remaining old representative nodes;
(F9) receiving a node list to which an electronic signature by the remaining old representative node is added;
(F10) Checking whether the electronic signature by all the remaining old representative nodes is added to the received node list;
(F11) A distributed authentication method comprising: a step of cooperating with each other between the predetermined number of representative nodes to create a distributed authentication system electronic certificate. The distributed authentication method according to claim 32, wherein
(G) performing the operation when updating the representative node,
(G1) an initial state step during the representative node update operation;
(G2) selecting a node as a new representative node;
(G3) transmitting a representative node designation confirmation message to another representative node;
(G4) receiving a representative node nomination confirmation response;
(G5) confirming whether a message rejecting the selected node is added to the received representative node nomination confirmation response;
(G6) transmitting a representative node nomination request to the selected node;
(G7) receiving a representative node nomination response from the selected node;
(G8) confirming whether a message refusing to become a representative node is added to the received representative node nomination response;
(G9) A step of confirming whether or not the number of representative nodes has reached a predetermined number. The distributed authentication method according to claim 32, wherein
(H) performing the operation when leaving the representative node,
(H1) an initial state step at the time of the representative node leaving operation;
(H2) receiving a node list to which electronic signatures of all representative nodes are added from the representative node;
(H3) adding an electronic signature to the received node list;
(H4) a step of transmitting the node list to which the electronic signature has been added to the representative node that has transmitted the node list to which the electronic signatures of all the representative nodes have been transmitted. .   A distributed authentication program for causing a computer to execute the distributed authentication method according to any one of claims 32 to 40.

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