Cyclic Obfuscation for Creating SAT-Unresolvable Circuits

Kaveh Shamsi, Meng Li, Travis Meade, Zheng Zhao, David Z. Pan, Yier Jin
2017 Proceedings of the on Great Lakes Symposium on VLSI 2017 - GLSVLSI '17  
Logic locking and IC camouflaging are proactive circuit obfuscation methods that if proven secure can thwart hardware attacks such as reverse engineering and IP theft. However, the security of both these schemes is called into question by recent SAT based attacks. While a number of methods have been proposed in literature that exponentially increase the running time of such attacks, they are vulnerable to "find-and-remove" attacks, and only slightly hide the circuit functionality. In this
more » ... we present a novel approach towards creating SAT attack resiliency based on creating densely cyclic obfuscated circuit topologies by adding dummy paths to the circuit. Our methodology is applicable to both IC camouflaging and logic locking. We demonstrate that cyclic logic locking creates SAT resilient circuits with 40% less area and 20% less delay compared to an insecure XOR/XNOR-obfuscation with the same key length. Furthermore, we show that cyclic IC camouflaging can be implemented at the layout level with no substrate area overhead and little delay and power overhead with respect to the original circuit. • We present cyclic obfuscation as the first topological, wire-based approach to creating SAT attack resiliency;
doi:10.1145/3060403.3060458 dblp:conf/glvlsi/ShamsiLMZPJ17 fatcat:x3wiqljbqndhnejisxpgrgyuh4