MaxSense: Side-channel Sensitivity Maximization for Trojan Detection Using Statistical Test Patterns

Detection of hardware Trojans is vital to ensure the security and trustworthiness of System-on-Chip (SoC) designs. Side-channel analysis is effective for Trojan detection by analyzing various side-channel signatures such as power, current, and delay. In this article, we propose an efficient test generation technique to facilitate side-channel analysis utilizing dynamic current. While early work on current-aware test generation has proposed several promising ideas, there are two major challenges in applying it on large designs: (i) The test generation time grows exponentially with the design complexity, and (ii) it is infeasible to detect Trojans, since the side-channel sensitivity is marginal compared to the noise and process variations. Our proposed work addresses both challenges by effectively exploiting the affinity between the inputs and rare (suspicious) nodes. The basic idea is to quickly find the profitable ordered pairs of test vectors that can maximize sidechannel sensitivity. This article makes two important contributions: (i) It proposed an efficient test generation algorithm that can produce the first patterns in the test vectors to maximize activation of suspicious nodes using an SMT solver, and (ii) it developed a genetic-algorithm based test generation technique to produce the second patterns in the test vectors to maximize the switching in the suspicious regions while minimizing the switching in the rest of the design. Our experimental results demonstrate that we can drastically improve both the side-channel sensitivity (62× on average) and time complexity (13× on average) compared to the state-of-the-art test generation techniques.