a signature verification system to accompany a computer - based training system to monitor the identity of the training system user . using a stylus and digitizing pad as a computer input device , the verification system accepts a user &# 39 ; s signature made under supervised conditions , and the computer generates various discriminator data associated with the singature , such as time to write signature , signature density and signature size . the verified , supervised signature and associated discriminator data are stored in encrypted format for security against tampering . during sessions on the training system the user is required to enter a signature at random times . again , corresponding discriminator data for these session signatures is generated by the computer , and the session signature and associated corresponding discriminator data are also likewise encrypted and stored . at a later time , e . g ., after the user has completed the training course , the discriminator data corresponding to the verified signature is compared to the discriminator data corresponding to a session signature , and any anomalous session signatures detected are flagged to alert the training course administration personnel to make visual comparison of the respective signatures .