A management system, comprising: one or more vehicles (100a, 100b, 100c); and one or more authentication servers (200a, 200b, 200c) remote from the one or more vehicles (100a, 100b, 100c), the one or more vehicles (100a, 100b, 100c) being connected to the one or more authentication servers (200a, 200b, 200c) by a network, wherein each of the one or more vehicles (100a, 100b, 100c) includes a first communication circuit that performs communication with at least one authentication server of the one or more authentication servers (200a, 200b, 200c), a plurality of electronic control units (ECUs) (111, 121, 131, 141, 151) connected to a network inside a vehicle (100a, 100b, 100c), a detection circuit that, when one or more electronic control units of the plurality of electronic control units (111, 121, 131, 141, 151) have been replaced, detects the replaced one or more electronic control units among the plurality of electronic control units (111, 121, 131, 141, 151), and a transaction data generating circuit that generates first transaction data including a first identifier that uniquely identifies each of the replaced one or more electronic control units (111, 121, 131, 141, 151) which the detection circuit has detected, and transmits the generated first transaction data to the at least one authentication server (200a, 200b, 200c) via the first communication circuit, and wherein each of the at least one authentication server (200a, 200b, 200c) includes a second communication circuit that performs communication with each of the one or more vehicles (100a, 100b, 100c), a verifying circuit that verifies validity of the first transaction data obtained by at least one vehicle of the one or more vehicles (100a, 100b, 100c), and a recording circuit that, upon verifying that the first transaction data is valid by the verifying circuit, records the first transaction data in a recording device. one or more vehicles (100a, 100b, 100c); and one or more authentication servers (200a, 200b, 200c) remote from the one or more vehicles (100a, 100b, 100c), the one or more vehicles (100a, 100b, 100c) being connected to the one or more authentication servers (200a, 200b, 200c) by a network, wherein each of the one or more vehicles (100a, 100b, 100c) includes a first communication circuit that performs communication with at least one authentication server of the one or more authentication servers (200a, 200b, 200c), a plurality of electronic control units (ECUs) (111, 121, 131, 141, 151) connected to a network inside a vehicle (100a, 100b, 100c), a detection circuit that, when one or more electronic control units of the plurality of electronic control units (111, 121, 131, 141, 151) have been replaced, detects the replaced one or more electronic control units among the plurality of electronic control units (111, 121, 131, 141, 151), and a transaction data generating circuit that generates first transaction data including a first identifier that uniquely identifies each of the replaced one or more electronic control units (111, 121, 131, 141, 151) which the detection circuit has detected, and transmits the generated first transaction data to the at least one authentication server (200a, 200b, 200c) via the first communication circuit, a first communication circuit that performs communication with at least one authentication server of the one or more authentication servers (200a, 200b, 200c), a plurality of electronic control units (ECUs) (111, 121, 131, 141, 151) connected to a network inside a vehicle (100a, 100b, 100c), a detection circuit that, when one or more electronic control units of the plurality of electronic control units (111, 121, 131, 141, 151) have been replaced, detects the replaced one or more electronic control units among the plurality of electronic control units (111, 121, 131, 141, 151), and a transaction data generating circuit that generates first transaction data including a first identifier that uniquely identifies each of the replaced one or more electronic control units (111, 121, 131, 141, 151) which the detection circuit has detected, and transmits the generated first transaction data to the at least one authentication server (200a, 200b, 200c) via the first communication circuit, generates first transaction data including a first identifier that uniquely identifies each of the replaced one or more electronic control units (111, 121, 131, 141, 151) which the detection circuit has detected, and transmits the generated first transaction data to the at least one authentication server (200a, 200b, 200c) via the first communication circuit, and wherein each of the at least one authentication server (200a, 200b, 200c) includes a second communication circuit that performs communication with each of the one or more vehicles (100a, 100b, 100c), a verifying circuit that verifies validity of the first transaction data obtained by at least one vehicle of the one or more vehicles (100a, 100b, 100c), and a recording circuit that, upon verifying that the first transaction data is valid by the verifying circuit, records the first transaction data in a recording device. a second communication circuit that performs communication with each of the one or more vehicles (100a, 100b, 100c), a verifying circuit that verifies validity of the first transaction data obtained by at least one vehicle of the one or more vehicles (100a, 100b, 100c), and a recording circuit that, upon verifying that the first transaction data is valid by the verifying circuit, records the first transaction data in a recording device.