Golden Model-Free Hardware Trojan Detection by Classification of Netlist Module Graphs

In a world where increasingly complex integrated circuits are manufactured in supply chains across the globe, hardware Trojans are an omnipresent threat. State-of-the-art methods for Trojan detection often require a golden model of the device under test. Other methods that operate on the netlist without a golden model cannot handle complex designs and operate on Trojan-specific sets of netlist graph features. In this work, we propose a novel machine-learning-based method for hardware Trojan detection. Our method first uses a library of known malicious and benign modules in hierarchical designs to train an eXtreme Gradient Boosted Tree Classifier (XGBClassifier). For training, we generate netlist graphs of each hierarchical module and calculate feature vectors comprising structural characteristics of these graphs. After the training phase, we can analyze the synthesized hierarchical modules of an unknown design under test. The method calculates a feature vector for each module. With this feature vector, each module can be classified into either benign or malicious by the previously trained XGBClassifier. After classifying all modules, we derive a classification for all standard cells in the design under test. This technique allows the identification of hardware Trojan cells in a design and highlights regions of interest to direct further reverse engineering efforts. Experiments show that this approach performs with >97 % Sensitivity and Specificity across available and newly generated hardware Trojan benchmarks and can be applied to more complex designs than previous netlist-based methods while maintaining similar computational complexity.