TAMPER RESISTANCE DEVICE AND METHOD FOR OPERATING THE SAME

摘要

PURPOSE: A tamper resistance device and a method for operating the same are provided to prevent data stored in a memory of an electronic device from being flowed out by an attack from an exterior or an illegal treatment. CONSTITUTION: An electronic device has a processor(114) which stores data in a memory(115) or reads/processes stored data. The electronic device is covered by an instrument(101). A luminous element(103) for emitting a light to an internal surface is included in the instrument(101). A light(109) emitted from the luminous element(103) is contacted with an internal surface(102) of the instrument(101) and the electronic device and dispersed to two-dimensional space or three-dimensional space. A partial portion of the dispersed light is collected in a light receiving element(111). An amount of a light collected to the light receiving element(111) is measured by a measuring device(112) and compared with a critical value in a comparator(113). In the case that the measured light amount is beyond tolerance, the comparator(113) outputs a predetermined signal to the processor(114). The processor(114) deletes data stored in the memory(115) in accordance with a signal from the comparator(113). The luminous element(103) is operated by a voltage being applied from an external power(107) or an internal power(106). If a level of the voltage become low or the power is stopped, a voltage comparison circuit(108) senses the variation and supplies a power from the internal power(106). A variable resistor(104) applies a power being supplied from the external power(107) or the internal power(106) to the luminous element(103) fixedly. The variable resistor(104) is controlled by a signal generated from a variable generator(105).