Abstract: A smart credit card device for allowing its owner to safely make credit transactions, which comprises a display screen; a memory for storing permanent data of the device and its owner and unique temporary dat regarding an impending specific transaction; a wireless transceiver for being in data communication with the credit company through a point o sale; input components for allowing the owner to input data essential fo performing the transactions; a processor for controlling the operation o the card device; and a power source such as a battery or a solar cell arra with a backup battery for supplying DC power to the card device.