Measuring Relative Pen Pressure to Authenticate Signatures

This study exploits the capacity of the confocal laser scanning microscope (CLSM) to accurately measure the z-axis of pen pressure indentations in paper. Depth values measured at various sites of signatures are compared to the maximum depth of each signature. By measuring these “relative” depth values of multiple genuine signatures, a writer’s master pattern of pen pressure emphasis can be uniquely portrayed in a quantified manner. “Relative” depth values of simulated and traced signatures are similarly measured and are generally found to be clearly distinguishable from genuine signatures.