A Validation Method in Electronic Commercial Transaction and a Method for Purchasing by Installment and a Method for Issuing Certificates Using the Validation Method and Systems thereof

摘要

PURPOSE: A certification, installment sale, and certificate issuing method and system are provided to certificate a customer by using a flash USB(Universal Serial Bus) drive, and to enable the customer to purchase a commodity by installment. CONSTITUTION: The method comprises several steps. A customer connects a portable flash USB drive, storing a certificate, to a USB port of a terminal, and accesses a service server over the internet(S21). The service server requests the terminal to transmit the certificate(S22). Then, the terminal transmits the certificate to the service server(S23). The service server transmits the received certificate to a certification server(S24). The certification server checks whether the certificate is forged or not(S25). The certification server transmits the certification result to the service server(S26). Then the service server offers an electronic transaction to the customer according to the certification result.