A Survey on AI-Augmented Secure RTL Design for Hardware Trojan Prevention

Once, discreet circuit elements, called components, were heaped up on boards inside steel cages using wire-lead technology in just five short years. Fast forward to today, and your computer CPU fits about half an inch square on a chip. Both this constant miniaturization of electronic circuits and the rapid growth in the prevalence of third-party intellectual property parts have made hardware protection more worrisome than ever.Among all these issues, Hardware Trojans (HTs)—which represent corrupted or harmful additions during various design and fabrication stages—pose significant threats to system integrity, privacy of data, and essential infrastructure. Recent studies have investigated machine learning (ML) and artificial intelligence (AI) techniques designed to enable Hardware Trojans to be found, located, and eliminated in all stages from the register transfer level (RTL) and beyond.This survey gives an in-depth look at how AI can enhance RTL security. It classifies these AI-based techniques into four main categories:Graph-Based Techniques:GNNs, for instance, can be used to estimate the topology of circuits, extract structural characteristics, and thus find where some corruption has occurred.The SALTY framework applies Jumping-Knowledge GNNs to improve the accuracy location for hardware Trojans.Deep Learning in Side-Channel and Power-Analysis Techniques:Deep learning methods—such as Siamese Neural Networks (SNNs) and Long Short-Term Memory (LSTM) models—have been developed to detect abnormalities brought about by Trojans in power consumption or electromagnetic (EM) radiation, granting non-invasive practices clear security benefits.Studies show that these techniques are superior to the traditional golden-model side-channel detection techniques.Machine Learning Analysis of RTL Code:In conjunction with AI, research teams are now building nearest-neighbor classifiers and decision trees and using reinforcement learning (RL) to recognize occurrences of Trojans inside RTL code.Some research uses Verilog/VHDL conditional statements as features for ML, making it possible for early warning signals to be effectively detected and introducing a proactive security mechanism during the design phase.Comprehensive Security Measures and Logic Locking:A step-by-step methodology has evolved for prevention measures such as logic locking and layout hardening, which aims against a splendid prospect within reach.The TroLLoc framework uses logic obfuscation combined with security-aware placement and routing, thus mitigating security exposures post-design.However, comprehensive studies point out several outstanding problems: key recovery attacks and unintended data leakage related to security in logic locking.In this way, the paper evaluates various AI-driven security strategies in an organized, facilitative manner, thereby highlighting significant challenges and proposing future research directions.