| 摘要 |
<P>PROBLEM TO BE SOLVED: To derive a value of which uniqueness of a device is enhanced. <P>SOLUTION: An IC card includes an oscillation circuit containing a plurality of oscillators having intrinsic oscillation frequency caused by variation in manufacture. Two of the plurality of oscillators are selected, and the selected oscillators are oscillated, to obtain an actual measurement count value C based on the oscillation frequency (steps S600-S605). Then, a response value Re and a corrected count value Cc are derived which is obtained by correcting the actual measurement count value C that has been obtained based on a correction value Cave, which is a value based on an average of the frequencies when an oscillator having the same arrangement and wiring as a selected oscillator of a plurality of IC cards 20 is oscillated (steps S610-S625). <P>COPYRIGHT: (C)2013,JPO&INPIT |
