1. A fingerprint data synthesis method, comprising the steps of: extracting minutiae from each of a plurality of fingerprint images to produce fingerprint data including information regarding the minutiae for each of the fingerprint images; investigating a correspondence of the minutiae between the plurality of fingerprint data to search for the same minutiae included commonly in two or more of the plurality of fingerprint data as common minutiae; selecting one of the common minutiae as a minutia representative of the common minutiae to synthesize the plurality of fingerprint data to produce one synthetic fingerprint data; and validating the synthetic fingerprint data.