Abstract: Pieces of information on multiple file management systems are managed by one contract in a distributed ledger. An administrator terminal includes: a file management system generation unit that issues a contract generation transaction for generating, in blockchain data, a contract in which a network identifier that identifies a file management system is associated with an identifier of a participant terminal in a blockchain system, and notifying the participant terminal of the network identifier and an identifier of the contract; and a file management control unit that issues a registration transaction for registering, in the contract, connection information of the administrator terminal in the file management system, acquires connection information of the participant terminal in the file management system from the contract, and establishes a P2P connection with the participant terminal based on the acquired connection information.

Abstract: Pieces of information on multiple file management systems are managed by one contract in a distributed ledger. An administrator terminal includes: a file management system generation unit that issues a contract generation transaction for generating, in blockchain data, a contract in which a network identifier that identifies a file management system is associated with an identifier of a participant terminal in a blockchain system, and notifying the participant terminal of the network identifier and an identifier of the contract; and a file management control unit that issues a registration transaction for registering, in the contract, connection information of the administrator terminal in the file management system, acquires connection information of the participant terminal in the file management system from the contract, and establishes a P2P connection with the participant terminal based on the acquired connection information.

Abstract: A settlement system includes a service provider device 2 which transmits a template information transaction including a template of a transaction to a network 4 of a first blockchain, a user device which transmits, to the network 4 of the first blockchain, a payment information transaction that includes an electronic signature generated by using the template of the transaction and a payment amount, and a smart contract 41, wherein the smart contract 41 verifies the electronic signature by using the payment amount and the template of the transaction, the service provider device 2 generates a settlement transaction by using the template of the transaction, the electronic signature and the payment amount, and transmits the settlement transaction to a network 3 of a second blockchain, a plurality of output conditions are set to the template of the transaction, and the settlement transaction becomes usable when any one of the plurality of output conditions is satisfied.

Abstract: Pieces of information on multiple file management systems are managed by one contract in a distributed ledger. An administrator terminal includes: a file management system generation unit that issues a contract generation transaction for generating, in blockchain data, a contract in which a network identifier that identifies a file management system is associated with an identifier of a participant terminal in a blockchain system, and notifying the participant terminal of the network identifier and an identifier of the contract; and a file management control unit that issues a registration transaction for registering, in the contract, connection information of the administrator terminal in the file management system, acquires connection information of the participant terminal in the file management system from the contract, and establishes a P2P connection with the participant terminal based on the acquired connection information.

Abstract: A registration terminal according to the present embodiment is connectable to a first distributed ledger network and a second distributed ledger network. The registration terminal includes a registration unit, a first control unit, and a second control unit. The registration unit registers a file in an external storage service. The first control unit generates a registration transaction including a file identifier assigned to the file by the storage service and a verification key, and transmits the registration transaction to the first distributed ledger network. The second control unit generates a token transaction related to generation of a token and including a signature object message including the file identifier and a signature value obtained by digitally signing the signature object message with a signature key, and transmits the token transaction to the second distributed ledger network.

Abstract: Upon receiving a usage request that includes a file identifier and a version identifier from a user terminal 20, a control server 10 transmits a file request that is based on the usage request to a file management system, and transmits a permission information request that is based on the usage request to a distributed ledger system. Upon receiving the file request, the file management system acquires the file that corresponds to the combination of the file identifier and the version identifier and transmits the file to the control server 10. Upon receiving the permission information request, the distributed ledger system acquires permission information that corresponds to the combination of the file identifier and the version identifier from a distributed ledger, and transmits the permission information to the control server 10. The control server 10 transmits the file to the user terminal 20 if the user of the user terminal has viewing permission based on the permission information.

Abstract: A data sharing system includes a plurality of IoT networks 20, and a plurality of management terminals 1 connected to a blockchain network 10. In the data sharing system, each management terminal 1 includes a reception unit 12 that receives a transaction including IoT terminal information related to an IoT terminal 2 from at least one IoT network 20 of the plurality of the IoT networks 20, a communication unit 13 that transmits and receives the transaction to/from another management terminal 1, a block generation unit 14 that attempts to generate a block including the transaction, a block verification unit 15 that verifies a block generated by another management terminal 1, and a distributed ledger 16 that stores the generated blocks.

Abstract: A data registration system of the present embodiment includes a control device 20 and a cooperating device 30. The control device 20 includes a communication unit 21 that receives a data registration request to which an electronic signature of a user is added, a verification unit 22 that verifies identity of the user, a transaction generation unit 23 that, if identity of the user is verified, takes out data included in the data registration request, transmits the data to the cooperating device 30 to store the data in the cooperating device 30, generates a transaction based on the data registration request, and adds an electronic signature to the transaction, the transaction including information for accessing the data stored in the cooperating device 30, and a blockchain control unit 24 that issues the transaction to a blockchain network. The cooperating device 30 includes a communication unit 31 that receives the data and a storage unit 33 that stores the data in association with the transaction.

Abstract: When an updated file that is an updated version of an original file is registered in a distributed file management system 100, a difference creation unit 222 creates a difference file between the original file and the updated file, a route object creation unit 223 creates a route object that includes an ID of the original file and an ID of the difference file, and a distributed file management client 11 causes the difference file and the route object to be registered in the distributed file management system 100.

Abstract: A permission terminal 4 includes a generation unit 423 that generates access information for content using a content public key of the content and a user public key of a browser of the content, and a registration unit 424 that registers the access information in a blockchain. The access information includes an aggregate public key in which the content public key and the user public key are aggregated, a message for the content, and a content signature in which the message is signed with a content private key corresponding to the content public key.

Abstract: A consensus is formed for a private database shared within a group. A block verification device includes: a private database shared within a group; a communication unit receiving a list of transactions from an overall leader device; a transaction processing unit executing the transactions identified based on the list and outputting the execution results; and a block processing unit generating a proposal including a list, a digest of the private database after execution of the transactions, and a private dataset included in the transactions. The communication unit transmits the proposal to another block verification device belonging to the same group, and transmits the list, the digest of the private database, and the digest of the private dataset to all the other block verification devices when it is determined that a consensus for the proposal is formed.

Abstract: Pieces of information on multiple file management systems are managed by one contract in a distributed ledger. An administrator terminal (1) includes: a file management system generation unit (122) that issues a contract generation transaction for generating, in blockchain data (B), a contract in which a network identifier that identifies a file management system (9) is associated with an identifier of a participant terminal (10) in a blockchain system (6), and notifying the participant terminal (10) of the network identifier and an identifier of the contract; and a file management control unit (123) that issues a registration transaction for registering, in the contract, connection information of the administrator terminal (1) in the file management system (9), acquires connection information of the participant terminal (10) in the file management system (9) from the contract, and establishes a P2P connection with the participant terminal (10) based on the acquired connection information.

Abstract: A history of data can be tracked easily on a blockchain. In a blockchain system, a distributed ledger 11 includes a state database that stores a state of a smart contract for each token. A user terminal 1 includes a transaction issue unit 13 that issues a transaction that updates a token. An approval terminal 2 includes an update unit 154 that updates the token in the state database, and a block generation unit 153 that generates the block including the transaction and causes the block and the updated state database to be reflected in the distributed ledger 11. The update unit 154 sets tracking data in the token in the state database, the tracking data including an update block number and token information on the token.

Abstract: A contribution degree of content according to a purchase situation of a content is calculated. A blockchain system includes a registration apparatus 1 and a contribution degree calculation apparatus 2. The registration apparatus 1 includes an acquisition unit 15 configured to acquire content purchase information and a transaction issuance unit 13 configured to issue a transaction including a purchaser ID and a content ID based on the content purchase information. The contribution degree calculation apparatus 2 includes a history acquisition unit 24 configured to acquire history information indicating that a purchaser with the purchaser ID purchases a different type of content associated with the content ID from a distributed ledger in which the transaction is reflected and a contribution degree calculation unit 25 configured to calculate a contribution degree of the content according to a purchase sequence of the content associated with the content ID by using the history information.

Abstract: A settlement system includes a service provider device 2 which transmits a template information transaction including a template of a transaction to a network 4 of a first blockchain, a user device which transmits, to the network 4 of the first blockchain, a payment information transaction that includes an electronic signature generated by using the template of the transaction and a payment amount, and a smart contract 41, wherein the smart contract 41 verifies the electronic signature by using the payment amount and the template of the transaction, the service provider device 2 generates a settlement transaction by using the template of the transaction, the electronic signature and the payment amount, and transmits the settlement transaction to a network 3 of a second blockchain, a plurality of output conditions are set to the template of the transaction, and the settlement transaction becomes usable when any one of the plurality of output conditions is satisfied.

Abstract: A history of data can be easily traced on a blockchain. A blockchain system includes a user terminal 1 and an approval terminal 2. The user terminal 1 includes a transaction issuing unit 13 that issues a transaction for updating a value of a variable of a smart contract. The approval terminal 2 includes a block generation unit 153 that generates a block including the transaction and updates the value of the variable, and reflects the block and an update block number of the block in which the value of the variable is updated to a distributed ledger 11 of a terminal of the blockchain system.

Abstract: Content data is registered in a file management system 8, an identifier of a user in the file management system 8 is registered in blockchain data B, and a right-holder terminal 1 includes a permission request receiving unit 122 that receives, from the file management system 8, permission request data for the content including an identifier of the user, a verification unit 123 that verifies that the identifier of the user registered in the blockchain data B corresponds to the identifier of the user included in the permission request data, and an permission issuing unit 124 that transmits, to the file management system 8, permission data for permitting a use of the content by the user.

Abstract: A proprietor terminal 1 stores state data Bs in which an identifier of a contract executed in a blockchain system 6, a hash value of control target file data that specifies content data managed by the contract, and an identifier of a proprietor and an identifier of a user of the content data in the file management system 9 are associated with one another, and includes a route object generation unit 123 that generates reference destination data R having the identifier of the contract and generates route object data Obj having the reference destination data R and a link name and the hash value of the control target file data.

Abstract: A blockchain is used to distribute a right to content data. A right holder terminal, an assignee terminal, and a blockchain control terminal stores a blockchain that is synchronized among the right holder terminal, the assignee terminal, and the blockchain control terminal. The blockchain includes a transaction set with a smart contract program for distributing the right. The blockchain control terminal includes a token issuance unit generating token data that includes match information for the content data and a type of right to be distributed, is set with an address of a right holder as owner information, and is identified by a token identifier, and registering the token data corresponding to the token identifier with the blockchain.

Abstract: A digital watermark is applied to a video to be distributed without re-encoding. A content distribution device 1 receives a content acquisition request to request video content, distributes the video content based on the content acquisition request, generates and distributes a watermark video with a watermark ID embedded, and causes watermark-video-related information including the watermark ID to be recorded, and a content playback device 2 transmits the content acquisition request, receives the video content and the watermark video, plays back and displays the video content, and superimposes the watermark video on the video content for playback and display.