ReTrustFSM: Toward RTL Hardware Obfuscation-A Hybrid FSM Approach

Hardware obfuscating is a proactive design-for-trust technique against IC supply chain threats, i.e., IP piracy and overproduction. Many studies have evaluated numerous techniques for obfuscation purposes. Nevertheless, de-obfuscation attacks demonstrated their insufficiency. This paper proposes register-transfer (RT) level finite-state-machine (FSM) called ReTrustFSM that allows designers to obfuscate at the earliest possible stage. combines three types of secrecy: explicit external secrecy via an key, implicit based on specific clock cycles, internal through concealed FSM transition function. So, robustness relies primary input patterns, cycle accuracy applying such stimuli. Additionally, defines cohesive relationship between features Boolean problems required time de-obfuscation, ensuring maximum execution oracle-guided attacks. Various are employed test ReTrustFSM’s robustness, including structural machine learning attacks, functional I/O queries (BMC), We also analyzed corruptibility overhead design-under-obfuscation. Our experimental results demonstrate acceptable overhead/corruption while resisting threat models.