Control method, data generation device, and recording medium

A data generation device that is communicably connected to a plurality of servers that record, every predetermined timing, a transaction data item selected from among transaction data items stored by the predetermined timing into a distributed ledger by incorporating the transaction data item into a block, the data generation device comprising:

• a processor;
• and
• a memory,
• wherein the processor generates first transaction data that includes latest information acquired by a first time, and transmits the first transaction data to a first server that is one of the plurality of servers,
• the processor checks content of a block recorded in the distributed ledger of the first server at a second time that happens one or more times after the first time to determine, when second transaction data next to the first transaction data is generated at the second time, whether a first block that is included when the first transaction data is recorded into the distributed ledger is different from a second block that is included when the second transaction data is recorded into the distributed ledger;
• and
• when it is determined that the first block is different from the second block, the processor generates, at the second time or thereafter, the second transaction data that includes latest information acquired after the first time, and transmits the second transaction data to the first server.

A non-transitory computer-readable recording medium having recorded thereon a program for causing a computer to execute a control method executed by a device in a system including the device and a plurality of servers that are communicably connected to the device, the plurality of servers recording, every predetermined timing, a transaction data item selected from among transaction data items stored by the predetermined timing into a distributed ledger by incorporating the transaction data item into a block, the control method comprising:

• generating first transaction data that includes latest information acquired by a first time, and transmitting the first transaction data to a first server that is one of the plurality of servers;
• checking content of the block recorded in the distributed ledger of the first server at a second time that happens one or more times after the first time to determine, when second transaction data next to the first transaction data is generated at the second time, whether a first block that is included when the first transaction data is recorded into the distributed ledger is different from a second block that is included when the second transaction data is recorded into the distributed ledger;
• and
• when it is determined that the first block is different from the second block, generating, at the second time or thereafter, the second transaction data that includes latest information acquired after the first time, and transmitting the second transaction data to the first server.