. . . "That is to say, the system is the one designed in such a way that the plaintext information (X) provided by the terminal device 1 installed at the home-banking in the home or at the branch offices, or the like, of financial institutions such as banks, etc. is enciphered and stored in an empty floppy FA that is magneto-optical disk of a large capacity, and said floppy is deciphered and read out int" . . .