Arrangement for protecting an electronic card and its use for protecting a terminal for reading magnetic and/or microprocessor cards

An arrangement for protecting a card comprising, on a printed circuit, an electronic circuit (10) including a volatile memory (12) containing programs or information to be protected, a resistive network (21, 22) comprising carbon film tracks on opposite faces of a substrate film (20) of polycarbonate surrounding the circuit (10), the tracks on one face being staggered with respect to the tracks of the other face, said resistive network and film being embedded in a resin (3), means connecting the resistive network (21, 22) to the electronic circuit (10) for detecting modifications to resistance of the resistive network in order to bring about a destruction of information contained within the volatile memory (12) wherein the means for detecting modifications to the resistance of the resistive network comprises a circuit having a resistor bridge (21, 22, 1046, 1044, 1049), a window comparator having an output, a multivibrator having an output and an electronic switch, said resistor bridge being connected to the window comparator (104), the output of the window comparator being connected to the multivibrator (107), and the output of said multivibrator adapted to be applied to the electronic switch (108) to interrupt power to the volatile memory (12).