Abstract: The present invention an electronic card for use in a secure data interchange system having a terminal adapted to receive and communicate with said electronic card, said card having means for communicating with said terminal and having a memory for storing program algorithms and data therein including valid terminal verification data and valid user identification request data; said electronic card comprising: (a) a microprocessor for monitoring for a predetermined period of time, immediately following insertion of said card in said terminal, an output from said terminal for a terminal verification message and being operable to erase said memory when said terminal verification message is not received within said predetermined period of time and being responsive to said terminal verification message received within said predetermined period of time, by comparing said received terminal verification message to said stored valid terminal verification message and being operable to erase said memory when said recei

Abstract: The present invention an electronic card for use in a secure data interchange system having a terminal adapted to receive and communicate with said electronic card, said card having means for communicating with said terminal and having a memory for storing program algorithms and data therein including valid terminal verification data and valid user identification request data; said electronic card comprising:

Abstract: Systems for interchanging information, for example, obtaining cash from a terminal by use of a portable device such as a credit card are well-known but suffer from being vulnerable to fraud. In the invention a highly secure information interchange system is achieved by utilizing an intelligent card as the portable device which verifies that the terminal is a valid one and the terminal in turn verifies that the card is valid. Unauthorized users are screened out by means of a physical characteristic scan of the user such as a fingerprint which is then compared with comparable data stored on the portable device. If an invalid terminal attempts to communicate with the card, the card erases the data and programs from its memory. All programs and data in the terminal are stored in memory which loses its contents when power is interrupted, thus improving the security of the system by making unauthorized use of a terminal very difficult.