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 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 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 device monitoring method includes: receiving a message transmitted from a first device to a second device and addressed to the second device; determining whether the message contains a device control command for controlling the second device; if the message contains the device control command, further determining whether to transmit the message to the second device based on a predetermined condition; and when the message is determined to be transmitted to the second device, transmitting the message to the second device. The predetermined condition includes a first condition that the first device is registered as a device having a predetermined function in a device list containing information about whether each of the devices is a device having the predetermined function. The message is determined to be transmitted to the second device when the predetermined condition is satisfied.

Abstract: An information management method collects log information of one or more home electrical apparatuses corresponding to service providers. Display screen data is generated which indicates a status of the log information. The display screen data includes groups of information which each contain information on an apparatus, a service provider corresponding to the apparatus, and log information output from the apparatus. Provision of the log information of each group is individually selectable. The display screen data is provided via a network to a display terminal that performs access to a server device. Information is received from the display terminal, which indicates that selection on whether or not provision of the log information is performed. Provision of the log information is not performed on the selected group when a determination is made that refusal of provision of the log information on the selected group is performed.

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: A control method in which each of an Internet of things (IoT) device and a user who uses the IoT device has a digital account includes: obtaining first transaction data for allowing the user who used the IoT device to transfer a first amount corresponding to a usage amount of the IoT device; specifying, from the first transaction data obtained, the digital account of the IoT device that is associated with an identifier uniquely assigned to hardware of the IoT device; and transferring the usage amount of the IoT device to the digital account of the IoT device by deducting the first amount from the digital account of the user and adding the first amount to the digital account of the IoT device based on the first transaction data obtained.

Abstract: A method includes: acquiring transaction data that includes value information regarding a value to be transferred from a second user to a first user; executing a first smart contract recorded in a first blockchain by recording the transaction data in the first blockchain; and executing a second smart contract recorded in a second blockchain different from the first blockchain based on the first smart contract. The second smart contract is a smart contract for transferring at least a portion of the value to be transferred from the second user to the first user, from a first account held by the first user to a third account held by a third user.

Abstract: Provided is an information processing method of one authentication server in a management system including one or more vehicles and one or more authentication servers. The method includes receiving, from one vehicle of the one or more vehicles, first transaction data which includes a first identifier that uniquely identifies each of one or more electronic control units that have been replaced out of a plurality of electronic control units connected to a network in the one vehicle, and indicates that the one or more electronic control units have been replaced among the plurality of electronic control units. The method further includes verifying validity of the first transaction data, and transmitting a duplicate of the first transaction data to one or more of other authentication servers when the validity of the first transaction data is verified in the verifying.

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 fraud detecting method for use in an in-vehicle network system including a plurality of electronic control units that communicate with each other via a network includes detecting whether a state of a vehicle satisfies a first condition or a second condition, and switching, upon detecting that the state of the vehicle satisfies the first condition or the second condition, an operation mode of a second electronic control unit connected to the network. A first mode in which a first type of detecting process for detecting a fraudulent message in the network is performed is switched to a second mode in which the first type of detecting process is not performed upon detecting that the state of the vehicle satisfies the first condition. Moreover, the second mode is switched to the first mode upon detecting that the state of the vehicle satisfies the second condition.

Abstract: A control method according to the present disclosure is executed by a first server of servers in a system including one or more IoT devices and the servers. The method includes: obtaining first transaction data including operation notification information and time information from each of the IoT devices, the operation notification information including identification information on the IoT device and a notification indicating that the IoT device is operating, the time information indicating a time when the IoT device has obtained the operation notification information; transferring the obtained first transaction data to second servers different from the first server; executing a first consensus algorithm together with the second servers; and recording a block containing the first transaction data in a distributed ledger of the first server, when the authenticity of the first transaction data is verified by the first consensus algorithm.

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.

Abstract: The present disclosure provides a management method for software versions to improve transaction safety of software. In the management method, among management apparatuses, a first token management apparatus obtains request information indicating a requested version requested by a user, and first transaction data indicating that the user provides predetermined number of tokens to a software developer who has developed the requested version is stored in distributed ledgers through execution of a consensus algorithm by the management apparatuses.

Abstract: A vehicle in a driving management system including one or more authentication servers and one or more vehicles capable of switching between a manual driving mode and an automatic driving mode is provided. The vehicle includes a communication unit that communicate with at least one authentication server of the one or more authentication servers, and a detecting unit that detects switching between the manual driving mode where manual driving is performed, and an automatic driving mode where automatic driving is performed, based on a message issued by at least one of the plurality of electronic control processors. The vehicle also includes a generating unit that generates transaction data including information indicating the detected switching, and an identifier indicating the vehicle, and transmits, to the at least one authentication server, the transaction data.

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 fraud detecting method for use in an in-vehicle network system including a plurality of electronic control units that communicate with each other via a network includes detecting whether a state of a vehicle satisfies a first condition or a second condition, and switching, upon detecting that the state of the vehicle satisfies the first condition or the second condition, an operation mode of a fraud-sensing electronic control unit connected to the network between a first mode in which a first type of detecting process for detecting a fraudulent message in the network is performed and a second mode in which the first type of detecting process is not performed. Moreover, in the second mode, a second type of detecting process having a different degree to which a fraudulent message is detectible than the first type of detecting process is performed.

Abstract: Provided is a data distribution method for a data distribution system which includes a device and a plurality of authentication servers.

Abstract: An electric lock control method includes: performing a first determination of whether a person is present in a predetermined region surrounding an electric lock, based on first information generated by an electronic device; when it is determined that a first person is present in the predetermined region in the performing of the first determination, performing a second determination of whether the first person is a person who is permitted to unlock the electric lock, based on second information related to movement of the first person; and controlling a state of the electric lock based on a result of the second determination, the state being a locked state or an unlocked state.

Abstract: A GM acquires a first certificate revocation list designating revoked public key certificates and distributed from a certificate authority server. The GM generates a second certificate revocation list produced by extracting information on a plurality of home electric appliances from the first certificate revocation list. The GM restricts communication with a device for which the public key certificate is revoked, by distributing the second certificate revocation list generated to the plurality of home electric appliances.