AUTHENTICATION SYSTEM, AUTHENTICATION DEVICE, AUTHENTICATION DATA PRODUCING DEVICE, AND AUTHENTICATION METHOD

摘要

When an encryption command is given, an encryption authentication data generation circuit generates encryption authentication data based on authentication basic data including a random-number portion, using an encryption rule. This encryption rule changes in accordance with the number of given encryption commands. A transmitting circuit (7) transmits the encryption authentication data. A receiving circuit (9) receives encryption authentication data transmitted from a second device (300). An inhibiting command output circuit (11) judges whether or not the encryption authentication data transmitted from the second device (300) coincides with encryption authentication data generated in the case where the encryption command is given to an encryption authentication data generation circuit of a first device (200) for the same number of times. If the result of judgment is negative, the inhibiting command output circuit (11) outputs an inhibiting command for inhibiting transmission of transmission target data.