AdaTrust: Combinational Hardware Trojan Detection Through Adaptive Test Pattern Construction

As society becomes increasingly reliant on products and systems that make use of integrated circuits, the defense against potential hardware Trojan attacks by an untrusted foundry becomes an important part of any certification flow for critical components. The slew of recent proposals notwithstanding, a satisfactory solution is still wanting as the solutions offered heretofore either require impractical design/test pattern cost or deliver insufficient detection capabilities, primarily challenged by the noise induced by process variation. The methodology put forth by this proposal aims to remedy this, leveraging an adaptive approach that applies superposition to perform a fine-grained circuit analysis and expose any extant Trojan circuitry. Iterative test pattern modifications, circuit response analysis, and adaptive decision-making are deployed, all embedded within the design-for-test and test pattern cost paradigms of a common industrial circuit. We demonstrate the efficacy of this technique on standard Trust-Hub benchmark circuits with combinational Trojans inserted in sequential designs, showing significant improvement over prior techniques. We also explore the potential cost-benefit tradeoffs that exist within such a methodology, with the intent to provide an efficient solution for an array of potential product markets. This methodology provides a reliable and effective means for Trojan detection, addressing an important piece of the overall circuit certification puzzle.