| 摘要 |
An encryption communication system including a host (1) and a data terminal card device (2) is disclosed. The host (1) includes a start information generation program circuit (11) for generating password generation start information which has not been used in the past. When the data terminal card' device (2) is connected to the host (1) for communication, a password generation program circuit (21) included in the card device (2) generates a password in accordance with the start information received from the host (1). The card device (2) sends the generated password to the host (1) for certification. If the received password is coincident with a password generated in the host (1), the host certifies the received password and allows communication to be held. An. encryption circuit (22) also included in the card device (2) controls a plurality of different encryption programs in a sophisticated way so as to execute time-varying irregular control, thereby generating encrypted data. <IMAGE> |
