To provide a secure system for a data processor, maintaining accuracy of identification by a fingerprint under various environments.

A fingerprint sensor 2 reads fingerprint data of a collated person. A thermometer 4 measures temperature, and a hygrometer 5 measures humidity. An identification threshold value setting means 11 selects an identification threshold value (a P threshold value) from a registrant information/threshold value setting information storage means 10 on the basis of the measured temperature and humidity. Similarly, a forgery identification threshold value setting means 12 selects a forgery identification threshold value (an N threshold value). A collation means 13 compares and collates the collated person fingerprint data with registrant fingerprint data to calculate a collation degree v, identifies the person when the collation degree v P, and rejects the identification when the collation degree v N. A collation count means 14 counts collation processing wherein N v P is satisfied. A data erasure means 15 erases prescribed data in a data storage means 6 when the counts exceeds a prescribed value.