Signature authenticating apparatus, signature authenticating method, signature authenticating program, and storage medium storing signature authenticating program

摘要

An entered signature is compared with registered signature data to calculate an evaluation value, and when the evaluation value for the entered signature is within the allowable range for successful authentication, it is determined whether aging has occurred. When aging is determined to have occurred, a warning message is displayed to urge re-registration of the signature. According to such a configuration, it is possible, when a change in signature is caused by aging, to avoid circumstances in which authentication becomes suddenly impossible.