Research on precautions against data disaster of logic security smart card

Taking the worldwide used logic security smart card as the subject, the author analyses the structure of the logic security card system. Considering the possible data damage in the card for the absence of anti-draw-out and anti-IFD-poweroff functions in use, a double data memory structure with check sum and the relevant reading/writing logic are put forward, which guarantees the correctness and availability of the data in the card when a data disaster happens.