Aim at the feasibility of using electromagnetic emanation side-channel to detect hardware Trojan in IC chips, the structure of EM side-channel signal of chip is analyzed and the leaked model about signal is designed. With explaining the principle of Karhunen-Loeve transform, a method that uses KL transform to obtain characteristic signal of EM emanation side-channel is introduced. It detects hardware Trojan by analyzing the difference between the characteristic signal of chip with and without Trojan. Experiments of detecting hardware Trojan in FPGA cipher chip show that we can distinguish effectively the difference between the EM signals of Trojan chip and genuine chip, then the Trojan in chip can be detected.
