History management method, history management apparatus and history management system

A history management method implemented by a computer to manage history information of a plurality of vehicles using blockchains,

• the method performed by at least one processor and comprising:
• generating a master block for being connected to a blockchain, from history information collected in a vehicle;
• recording, in the master block, vehicle identification information indicating the vehicle in which the history information is collected;
• per block, setting a storage destination of a backup block being a copy of the master block from among nodes communicable with the vehicle;
• together with the master block, storing backup blocks that are different in history information collecting vehicle from the master block in a block storage unit;
• together with a restore request, distributing the vehicle identification information of a particular vehicle of which the blockchain is to be restored, to the nodes each having the block storage unit thereof;
• and
• from among the backup blocks stored in the block storage unit, sending the backup block containing the vehicle identification information of the particular vehicle to a source of the restore request.

A history management apparatus that functions as one node in a network in which a plurality of vehicles are communicably connected, and that uses a blockchain to manage history information of a self-vehicle being one of the plurality of vehicles, the history management apparatus comprising:

• a block generation unit that generates a master block for being connected to the blockchain, from the history information collected in the self-vehicle;
• a storage destination setting unit that, per block, sets a storage destination of a backup block being a copy of the master block from among nodes communicable with the self-vehicle;
• a block storage unit that stores, together with the master block, backup blocks that are different in history information collecting vehicle from the master block;
• and
• a block sending unit that, based on a restore request distributed via a network, sends a backup block for a particular vehicle requested in the restore request from among the backup blocks stored in the block storage unit,
• wherein:
• when generating the master block, the block generation unit records, in the master block, identification information enabling identification of the backup blocks stored in the block storage unit.

A history management system that uses blockchains to manage history information of a plurality of vehicles, the history management system comprising:

• a block generation unit that generate a master block for being connected to a blockchain from history information collected in a vehicle and records, in the master block, vehicle identification information indicating the vehicle in which the history information is collected;
• a storage destination setting unit that, per block, sets a storage destination of a backup block being a copy of the master block from among nodes communicable with the vehicle;
• a block storage unit that, together with the master block, stores backup blocks that are different in history information collecting vehicle from the master block;
• and
• a request distribution unit that distributes, together with a restore request, the vehicle identification information of a particular vehicle of which the blockchain is to be restored, to the nodes each having the block storage unit thereof;
• and
• a block sending unit that, from among the backup blocks stored in the block storage unit, sending the backup block containing the vehicle identification information of the particular vehicle to the request distribution unit.