Hardware Trojan Horses (HTHs) are malicious modifications inserted in Integrated Circuit during fabrication steps. The HTHs are very small and can cause damages in circuit function. They cannot be detected by conventional testing methods. Due to dangerous effects of them, Hardware Trojan Detection has become a major concern in hardware security. In this paper, a new HTH detection method is presented based on side-channel analysis that uses path delay measurement. In this method, we find and observe the paths that Trojans have most effect on them. Most of the previous works add some structures to the circuit and need a large overhead cost. But, in our method, there is no modification in the circuit and we can use it for testing the circuits received after fabrication. The proposed method is evaluated with Xilinx FPGA over a number of test circuits. The results show that measuring the delays on 20 paths with an accuracy of 0.01[Formula: see text]ns can detect more than 80% of Trojans.
