Abstract: A data management method performed by a first authentication server included in a plurality of authentication servers each having a distributed ledger in a data management system including a device and the plurality of authentication servers includes: obtaining first transaction data generated by the device and including device data obtained or generated by the device; and generating a block including the first transaction data and recording the generated block in the distributed ledger, when the device data included in the first transaction data is first data indicated in an information type list which is a data list indicating data that is subject to recording in the distributed ledger and related to a predetermined contract.

Abstract: A control method that is used in a content management system including a plurality of servers, each holding a distributed ledger, and that is executed by one of the servers includes acquiring first transaction data from a providing device and storing the acquired first transaction data in the distributed ledger held by each server, the first transaction data including identification information for specifying content provided by the providing device and permission/prohibition information regarding whether to permit or prohibit the browsing of the content.

Abstract: A method includes: associating one or more data managers with mutually different models of a plurality of home appliances the one or more data managers managing data items generated by the plurality of home appliances; recording provision record information in which data identification information and manager identification information are associated with each other, the data identification information identifying each of one or more data items generated by the plurality of home appliances, the manager identification information identifying each of the one or more data managers; and determining, when the one or more data items include a used data item used by a data user, an amount to be transferred to a data manager that manages the used data item, based on the provision record information.

Abstract: The present disclosure provides a control method that is executed by one of a plurality of servers in a content management system that includes: the plurality of servers that own distributed ledgers; and a storing device that stores content, the control method including: acquiring transaction data that indicates that a providing device has provided content and includes at least identification information of the content provided by the providing device; and storing the transaction data acquired into the distributed ledgers of the plurality of servers.

Abstract: A control method includes: obtaining first transaction data that includes a first variable indicating first information on a first contract made between a first user and a second user, and a second variable set to a predetermined value indicating second information is undetermined; storing the first transaction data into the distributed ledger; executing storing processing of reading out the second variable, and storing it into a rewritable storage in a server; obtaining second transaction data that includes a third variable indicating third information on a second contract made between the first user and a third user, and a change command for changing the second variable, based on the third variable; storing the second transaction data into the distributed ledger; and executing change processing of changing, according to the change command, the second variable from the predetermined value, after the second transaction data is stored into the distributed ledger.

Abstract: A control method of a fund management system including a plurality of servers that hold a distributed ledger, and executed by one of the plurality of servers, includes: receiving transaction data, the transaction data pertaining to payment processing for payment of a token from one or more applicants of crowdfunding to a management account, and storing the transaction data that is received in the distributed ledger held in each of the plurality of servers; determining, using a smart contract, whether or not a target condition of the crowdfunding is met; and outputting information indicating a result of the determining.

Abstract: Provided is a control method which includes: obtaining battery information which is information regarding a battery; calculating a present residual value of the battery based on the battery information obtained; calculating a first residual value using a first model which has been trained, the first residual value being a residual value of the battery in a case where a user uses the battery with a tendency identical to a tendency of a plurality of other users; and issuing a token to the user according to an evaluation value calculated based on the present residual value and the first residual value calculated.

Abstract: A control method of an analysis device includes analyzing a binary code of each of a plurality of smart contracts stored in a first distributed ledger; obtaining, by using a result of the analyzing, items of commonization information expressing, in a common format, items of information provided by the plurality of smart contracts; and generating transaction data that includes the items of commonization information obtained and performing control of storing the transaction data generated into a second distributed ledger.

Abstract: A control method is executed by a first server among a plurality of servers in a system including the plurality of servers and a generating device that generates record information about usage records for users belonging to one group when a service provided by a business operator is used on a group basis. The method includes: obtaining, from the generating device, first record information about a first usage record of a service by a first user belonging to the one group; determining whether the first record information obtained is permitted under a rule based on contract content, stored in the first server, of a contract entered into by the first user and the business operator; and forwarding first transaction data including a determination result to a plurality of second servers and storing a first block including the first transaction data in a distributed ledger managed by the first server.

Abstract: A control method that, in an information management system including a plurality of servers each having a distributed ledger, is executed by a server from among the plurality of servers, includes: receiving first transaction data that includes identification information and permission or non-permission information, the identification information being associated with user information that is managed in the information management system and relates to a first user, the permission or non-permission information indicating whether provision of the user information to a second user is permitted; and storing the first transaction data received, in the distributed ledger in each of the plurality of servers.

Abstract: A control method according to the present disclosure includes: receiving, from a terminal operated by a first user who is one of parties that have concluded a first contract, first transaction data that includes a first smart contract corresponding to the first contract and a first electronic signature associated with the first user; executing a consensus algorithm with a plurality of other servers; and recording a block including the first transaction data in a distributed ledger. The first smart contract includes (i) content of the first contract which is a main contract, (ii) a variable that is provisional and used for identifying a second smart contract corresponding to a second contract which is to be newly concluded as a sub contract of the first contract, and (iii) a condition for creation of the second smart contract.

Abstract: A data management method performed by a first authentication server included in a plurality of authentication servers each having a distributed ledger in a data management system including a device and the plurality of authentication servers includes: obtaining first transaction data generated by the device and including device data obtained or generated by the device; and generating a block including the first transaction data and recording the generated block in the distributed ledger, when the device data included in the first transaction data is first data indicated in an information type list which is a data list indicating data that is subject to recording in the distributed ledger and related to a predetermined contract.

Abstract: A fault monitoring method is executed by a monitoring device in a fault monitoring system that includes a terminal used by a user, an appliance to be operated by the user, the monitoring device, and a plurality of authentication servers each including a distributed ledger, and includes: obtaining event information stored in the plurality of authentication servers and indicating an event generated in response to a request that includes a processing instruction for the user operating the appliance; obtaining state information indicating whether the appliance is faulty, from the appliance; generating first transaction data including the state information obtained and transmitting the first transaction data to the plurality of authentication servers; and transmitting the processing instruction included in the event information to the appliance, when the appliance is determined to be not faulty from the state information.

Abstract: A control method includes: receiving first information pertaining to a first contract from a first terminal used by a first user who is one of two parties who have agreed to the first contract; when consent of a party aside from the two parties is required to validate the first contract, identifying a second user as the party aside from the two parties with reference to a ledger storing information pertaining to a past contract, and transmitting the first information to a second terminal operated by the second user; obtaining second information in which a confirmation result indicating whether the second user consents to the first contract and a digital signature of the second user are added to the first information; and confirming the second information, and when the confirmation result indicates consent, setting the first contract as a valid contract and storing the second information in the ledger.

Abstract: A data management method performed by a first authentication server included in a plurality of authentication servers each having a distributed ledger in a data management system including a device and the plurality of authentication servers includes: obtaining first transaction data generated by the device and including device data obtained or generated by the device; and generating a block including the first transaction data and recording the generated block in the distributed ledger, when the device data included in the first transaction data is first data indicated in an information type list which is a data list indicating data that is subject to recording in the distributed ledger and related to a predetermined contract.

Abstract: A method includes: associating one or more data managers with mutually different models of a plurality of home appliances the one or more data managers managing data items generated by the plurality of home appliances; recording provision record information in which data identification information and manager identification information are associated with each other, the data identification information identifying each of one or more data items generated by the plurality of home appliances, the manager identification information identifying each of the one or more data managers; and determining, when the one or more data items include a used data item used by a data user, an amount to be transferred to a data manager that manages the used data item, based on the provision record information.

Abstract: A method for controlling one of voting servers in an electronic voting system is provided. The method includes receiving, from a terminal, transaction data including voting data, and determining, by a processor, a block to include the transaction data from among multiple blocks. The method further includes generating, using the processor, the block including the transaction data, and connecting the block to a blockchain, the blockchain being stored in a memory.

Abstract: Provided is a control method which includes: obtaining battery information which is information regarding a battery; calculating a present residual value of the battery based on the battery information obtained; calculating a first residual value using a first model which has been trained, the first residual value being a residual value of the battery in a case where a user uses the battery with a tendency identical to a tendency of a plurality of other users; and issuing a token to the user according to an evaluation value calculated based on the present residual value and the first residual value calculated.

Abstract: A control method according to the present disclosure includes: receiving, from a terminal operated by a first user who is one of parties that have concluded a first contract, first transaction data that includes a first smart contract corresponding to the first contract and a first electronic signature associated with the first user; executing a consensus algorithm with a plurality of other servers; and recording a block including the first transaction data in a distributed ledger. The first smart contract includes (i) content of the first contract which is a main contract, (ii) a variable that is provisional and used for identifying a second smart contract corresponding to a second contract which is to be newly concluded as a sub contract of the first contract, and (iii) a condition for creation of the second smart contract.

Abstract: A method for controlling one of a plurality of voting servers in an electronic voting system is provided. The method includes receiving, from a terminal, transaction data including voting data, and generating, using a processor, a block including the transaction data and dummy transaction data. The dummy transaction data including dummy voting data that is not associated with the voting data. The method further connects the generated block to a blockchain, the blockchain being stored in a memory.