On the Optimization of Behavioral Logic Locking for High-Level Synthesis

The globalization of the electronics supply chain is requiring effective methods to thwart reverse engineering and IP theft. Logic locking is a promising solution but there are still several open concerns. Even when applied at high level of abstraction, logic locking leads to large overhead without guaranteeing that the obfuscation metric is actually maximized. We propose a framework to optimize the use of behavioral logic locking for a given security metric. We explore how to apply behavioral logic locking techniques during the HLS of IP cores. Operating on the chip behavior, our method is compatible with commercial HLS tools, complementing existing industrial design flows. We offer a framework where the designer can implement different meta-heuristics to explore the design space and select where to apply logic locking. Our methods optimizes a given security metric better than complete obfuscation, allows us to 1) obtain better protection, 2) reduce the obfuscation cost.