Abstract: A dynamic signature/sign biometric verification system for detecting and preventing fraudulent transactions is described. The system comprises remote digital signature/sign input devices, a means to extract spatial and temporal features from the signature, a means to transmit the signature/sign features along with customer identifier information to a centralized signature/sign verification authority, a means for combining signature/sign feature verification with other forms of fraud detection technology, and a means for transmitting the results of a signature/sign verification back to the remote location where the signature/sign was captured. The system was primarily developed for use in payment card industries (e.g. credit cards, debit cards) but has applicability to other centralized signature/sign verification applications such as Automated Teller Machine authorizations and other identity theft detection and monitoring services.