Novel Variability Aware Path Selection for Self-Referencing Based Hardware Trojan Detection

Hardware Trojans can be inserted by an adversary at untrusted third-party fabrication houses. Many Side-channel analysis based detection techniques have been proposed in past to detect such Trojans. However, their efficiency is highly affected by process variations. Hardware Trojan (HT) inserted in an IC affects the path delays within the IC. In this work, we exploit the fact that the path delays of topologically symmetric paths in an IC will be affected similarly by process variations. We tend to choose paths that are minimally affected by process variations. In this paper, we propose a path selection technique for delay based HT detection technique. We further use the concept of self-referencing to improve detection accuracy as well as to eliminate the requirement of golden ICs. Simulations performed using ISCAS-85 benchmarks establish that the proposed method is achieving a true positive rate of 100% with a false positive rate less than 5%. We have considered maximum of 10% intra-die and 15% inter-die variations in threshold voltage (Vth).