FIELD: computer engineering. SUBSTANCE: device has semiconductor microchip, which has at least one data storage unit, which power supply and duplex data transmission to semiconductor chip and from semiconductor chip are provided by contacts 20 and remote data transmission units 2. Semiconductor chip is equipped with controlled switch 9, which state depends on output signal, which is connected to at least power supply contact 21 of logical circuit 8, in order to connect data storage unit 1 to contacts 20 or remote data transmission units 2. Goal of invention is achieved by design of controlled switch 9 which is in rest state, when no control signal exists, so that it provides connection of data storage unit 1 to remote data transmission units 2 in this position, and provides connection of contacts 20 to data storage unit 1 under control of logical circuit 8, only when power supply contact 21 is supplied. EFFECT: protection against unauthorized use of smart cards. 8 cl, 1 dwg
