A signature verification method is based on a comparison of the dynamics of a reference and a sample signature. Acceleration and pressure signals produced by a known person when writing his or her signature are stored and used as a reference signals. Then, at a later time, a person whose signature is to be verified writes his or her signature to produce acceleration and pressure signals that are compared to the reference signals. The process of comparison involves segmenting the two sets of signals to facilitate identifying regions of high probable correlation and then correlating corresponding segment pairs. Segmentation is based on pen lifts which represent reproducible timing marks in the signatures. According to the disclosed method, a pen or other writing instrument is used which produces a signal representative of the first time derivative of the pressure forces exerted on the stylus of the pen. The second time derivative of the pressure forces is computed from the measured signal. The first and second time derivatives are examined to detect quiet times indicative of lifting the pen from a writing surface. The detected quiet times are checked to determine if they have a time duration which exceeds a predetermined time period. The polarity and amplitude of the second time derivatives are tested to determine if they are positive and exceed a predetermined threshold at the beginning and end of each detected quiet time. Preferably, the steps of detecting quiet times, examining the duration of the quiet times, and testing the polarity and amplitude of the second derivatives are performed concurrently.