Patent US 3,955,178

A system is disclosed for authenticating a signature on the basis of its execution. Generally, the system senses the speed of the tip of a writing instrument as a criterion for developing an identification or characterization of the signature. As disclosed, a tablet is provided defining a surface which is scored orthogonally to create impulses (by pen contact) that relate to the speed of the tip of a pen. The impulses are sensed as an electrical signal which is processed to derive a characterization of the signature. In one disclosed embodiment, signatures are characterized by the number of impulses developed during a substantial portion of the signing interval. In another disclosed embodiment, signatures are characterized by the time required (in the course of executing a signature) to generate a predetermined number of impulses. In still another embodiment, a system is disclosed to include apparatus for deriving a developed code identification from the signature impulses along with structure for performing a comparison between "test" and "standard" characterizations. Each of the systems as disclosed include means for manifesting authenticity characteristics indicating the likely authenticity of a signature.