A cryptographic communication system includes an electronic device configured to output a certificate and a transaction including a first hash value in which a certificate is hashed certificate, and a node configured to first determine whether the electronic device generated the transaction based on the transaction and the certificate, to second determine whether information included in the transaction and information included in the certificate coincide, and to third add a block to a distributed ledger depending on the result of the first determining and the second determining. The block includes the transaction, and the electronic device is configured to generate the certificate such that the certificate includes an ID of the electronic device and a public key of the electronic device.