Abstract: A method and apparatus for electronic financial transaction processing systems used by customers of certain credit or electronic banking card-issuing institutions. The present invention involves two levels of secure interaction between the customer and the card-issuing institution. The first level of interaction involves the enrollment of a customer in the institution's electronic financial transaction processing system. The customer either selects or is issued a personal identification number and a card encoded with a personal key. The personal key and peronal identification number are used to generate a PIN transmission number and personal vertification number, which is stored in bank records. The second level of interaction involves the authorization of a customer's use of the electronic financial transaction processing system for executing an electronic transaction.

Abstract: The invention comprises a method for encrypting data for communication between a host computer and each of a plurality of remote terminals in a network. A method is provided for periodically generating a unique dynamic encryption key for each of said plurality of terminals using a system seed key residing only in the host computer. The dynamic encryption key generated for use by said terminal in encrypting data transmitted to said host computer and for decrypting data received from said host computer. The method includes storing at said terminal the dynamic key previously generated by said host for said terminal.