A verification method includes: obtaining log information items generated in a device; storing the log information items in storage, and storing, in a blockchain, converted information items obtained by converting the log information items; and conducting, at a predetermined frequency, verification as to whether at least one of a target log information item or a target converted information item has been tampered with, based on the target log information item and the target converted information item, the target log information item being included in the log information items and targeted for verification, the target converted information item being included in the converted information items and corresponding to the target log information item. A higher frequency is determined as the predetermined frequency when a time point at which the target converted information item was stored in the blockchain is closer to a current time at which the verification is conducted.