Signature verification method and apparatus utilizing both acceleration and pressure characteristics
Dynamic re-creation of signatures Patent #: 4156911
ApplicationNo. 06/371886 filed on 04/26/1982
US Classes:382/123, Sensing geometrical properties382/220Calculating weighted similarity or difference (e.g., don`t-care areas)
ExaminersPrimary: Boudreau, Leo H.
Attorney, Agent or Firm
International ClassesG07C 9/00 (20060101)
G06K 9/00 (20060101)
Foreign Application Priority Data1981-04-27 GB
AbstractA method for real-time signature verification uses a transducer pad in which the pressure of a stylus causes contact to be made between two resistive films. Such a transducer is energized by current pulses to sample pairs of X and Y coordinates every 5 milliseconds. The analogue voltage outputs are converted to digital form and processed under the control of a microprocessor to determine numerical parameters each representing a significant feature of the signature pattern. A set of specimen signatures is collected and from these the mean values and standard deviations of several relevant parameters are calculated and committed to memory. The parameters for a working signature are compared with the respective stored mean values for the individual concerned. Each deviation from a stored mean value is compared with the corresponding stored standard deviation in a non-linear scoring circuit. The aggregate score derived from the comparison of several parameters is compared with a preset threshold level to decide whether or not a working signature is genuine.