5 One example of an electronic transaction using an electronic authentication and notarization system shown in a flow chart is as shown in Fig.1.

(1) Mr.A and Corporation B wish to enter into a contract. First of all, each party receives from the other party an electronic certificate issued by an certification agency, and each of them confirms that the other contracting party is Mr.A or Mr.C, the representative of Corporation B. At this time, they confirm that the contents of the electronic certificate have not been altered by verifying a digital signature.

(2) Mr.A and Mr.C may ask the certification authority whether a certificate sent from the other party is valid, when they have any doubt about the validity of the contents of the electronic certificate received from the other party.

(3) Mr.A and Mr.C mutually confirm that the other party who has sent an electronic certificate is the person listed in the electronic certificate. Specifically, for instance, this is done in such a way in which data encrypted with Mr.A's private key is converted into a plaintext with Mr.A's public key and it is verified that its content matches that of the original plaintext.

(4) Mr.A and Mr.C encrypt their respective information on transaction with each other's public key, and exchange it between themselves. By doing so, they can negotiate a contract in secret, and finalize the details of the contract.

(5) When the details of the contract finalized, either Mr.A or Mr.C sends the details of the finalized contract by using the public key of the Notarial Acts Bureau to the Notarial Acts Bureau to apply for notarization and a fixed date on it.

(6) Upon confirming that a contract has been genuinely entered into, and its contents are not illegal, the Notarial Acts Bureau attaches a statement of certification and a fixed date to the data, generates a digital signature of a notary public in order to prevent any alteration, keeps the data in the database of the Notarial Acts Bureau, encrypts the data with Mr.A and Mr.C's public key, and then sends it to Mr.A and Mr.C.