TOIC: Timing obfuscated integrated circuits

To counter the threats of reverse engineering (RE) and Trojan in-sertion, researchers have considered gate-level obfuscation in inte-grated circuits (IC) as a viable solution. However, several techniques are present in the literature to crack the obfuscation with varying degree of success raising the concern about their secrecy. In this article, we have presented TOIC (Timing Obfuscated Integrated Circuits), a novel technique where sequential elements are obfuscated to hide the true timing paths in the design. TOIC can act as a standalone countermeasure against IC reverse engineering or can be incorporated with existing gate camouflaging techniques to maximize adversarial RE effort. Previous research has shown that limiting access to internal nodes can improve the adversarial RE effort at the cost of poor testability. TOIC can impose prohibitively large decamouflaging time complexity by limiting the controllability and observability over the internal nodes in an IC while preserving complete testability.