Blockchain is the technology that has data structure with anti-tampering and ensures high availability and integrity of the data which is verified and archived in a distributed network, and it is expected to be practically applied in a wide range of fields. Under such circumstances, aiming to contribute to the creation of new services using blockchain technology, we presented a basic method and procedure for identity verification of users in blockchains, utilizing the public certification service for individuals in Japan, called Japanese Public Key Infrastructure (JPKI).