Different role of friction and normal force for force-based signature verification

Compared with trajectory-based verification, force signal verification is a new approach in signature verification, which is expected to provide higher security. In order to understand which components of force signal is significant in force pattern, a novel pen is developed to detect three-dimensional force between pen-tip and the paper. Experiments are carried out to compare the verification performance between different force components with Dynamic Time Warping (DTW) algorithm. The existence of force features during writing is validated. The equal error rate in the case of using the normal force signal is lower than that of using the three-dimensional force signals about three times. The experiments results show that friction is important to maintain high verification for the signature verification based on the force feature during writing.