CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2018-135289 filed on Jul. 18, 2018, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a technology of history management for managing vehicle history information.

BACKGROUND

A known transaction recording system is described in, for example, Patent Literature 1 which uses a blockchain to record histories of transactions among a large number of nodes connected to a network. In the transaction recording system of Patent Literature 1, in order to reduce the amount of data retained in a respective node, the transaction histories in a particular network are retained only by the nodes arranged in the particular network.Patent Literature 1: JP2018-67108A

The inventors of the present disclosure have studied application of the blockchain technology as in Patent Literature 1 to vehicle history information preservation. In the system of Patent Literature 1 however, all of the blocks containing transaction histories in a particular network are copied to each of all of the nodes in the particular network. Because each of the nodes has all of the blocks, an increase in amount of communications or an increase in amount of data stored in each node is unavoidable. It is therefore difficult to apply such a system as Patent Literature 1 to preservation of the vehicle history information.

SUMMARY

It is an object of the present disclosure to provide a history management method and a history management apparatus suitable for preserving vehicle history information using a blockchain technology.

A history management method in one aspect is implemented by a computer to manage history information of a vehicle using a blockchain and is performed by at least one processor, the method comprising: generating a block for being connected to the blockchain, from the history information collected in the vehicle; per block, setting a storage destination of a backup of the generated block from among nodes communicable with the vehicle; and sending the backup of the block to the node that is set as the storage destination.

A history management apparatus in one aspect manages history information of a vehicle using a blockchain and comprises: a block generation unit that generates a block for being connected to the blockchain, from the history information collected in the vehicle; a storage destination setting unit that, per block, sets a storage destination of a backup of the block generated by the block generation unit from among nodes communicable with the vehicle; and a block sending unit that sends the backup of the block to the node that is set as the storage destination by the storage destination setting unit.

In the above forms, a storage destination of a backup of a block generated from history information of a vehicle is set per block from among nodes communicable with the vehicle. Therefore, cases where all of the blocks in a blockchain are copied to all of the nodes in a particular network are avoidable. Accordingly, an increase in amount of data stored in each node or an increase in amount of communications due to each node retaining all of the blocks is suppressible. Therefore, a history management method and a history management apparatus suitable for perverting vehicle history information using a blockchain technology are realized.

