Method for verifying a handwritten signature entered into a digitizer

A handwriting verification method which is less expensive to implement than previous methods, employs simpler algorithms than previous methods, and which requires fewer points than previous methods. The method includes the steps of determining a set of positional data points for a handwritten signature entered into the digitizer, determining a set of global variable values associated with the signature from the positional data points, determining head and tail strings having shape information for the signature, reading previously computed head and tail strings from a storage medium carried by the person, reading the verification information from the storage medium, determining a range of acceptance values for each global variable, and determining whether each of the global verification values lies within the range of acceptance. If at least one of the global verification values lies outside the range of acceptance, the method further includes the step of rejecting the subsequent signature as a forgery. If each of the global verification values lies within the range of acceptance, the method further includes the step of determining whether the head and tail strings of the subsequent signature equal the head and tail strings from the storage medium. If either of the head and tail strings of the subsequent signature are not equal to the head and tail strings from the storage medium, the method further includes the step of rejecting the subsequent signature as a forgery. Finally, if both the head and tail strings of the subsequent signature are equal to the head and tail strings from the storage medium, the method includes the step of accepting the signature as valid.