| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To allow for safe authentication even when an IC tag and a reader are apart from each other. <P>SOLUTION: The IC tag includes a mode switching circuit 204 which can detect electric power available for IC tag communication and activating/deactivating an encryption circuit 203. In short distance communication, radio wave is strong, and so the encryption circuit is activated. In long distance communication, radio wave is weak, and so the encryption circuit is deactivated, and minimum required functions are activated to use one-time key authentication not using encryption. Thus, an authentication mode is switched according to the strength of radio wave and the communication distance. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
