Investigation of obfuscation-based anti-reverse engineering for printed circuit boards

Prior work has shown that printed circuit board (PCB) reverse engineering can be accomplished with inexpensive home solutions as well as state-of-the-art technologies. Once the information of how components on a PCB are connected is determined, an adversary can steal the IP, clone the design, determine points of attack on a system, etc. Existing chip-level obfuscation techniques are not applicable to board level due to the significant differences between chips and PCBs. In this paper, we propose a PCB obfuscation approach that relies on permutation blocks to hide the interconnects among the PCB's circuit components. A detailed framework is provided to implement the proposed approach and evaluate its performance. Potential attacks and countermeasures are also discussed. Results obtained from five industrial reference designs show that it is nearly impossible to break the proposed approach by brute force, even under pessimistic assumptions. Our investigation also reveals that PCBs containing a programmable component with 64 pins (or more) are well-protected by our approach, making it suitable for a large percentage of systems and applications.