Oracle-guided incremental SAT solving to reverse engineer camouflaged logic circuits

Abstract

Layout-level gate camouflaging has attracted interest as a countermeasure against reverse engineering of combinational logic. In order to minimize area overhead, typically only a subset of gates in a circuit are camouflaged, and each camouflaged gate layout can implement a few different logic functions. The security of camouflaging relies on the difficulty of learning the overall combinational logic function without knowing which logic functions the camouflaged gates implement.