On the Effectiveness of the Satisfiability Attack on Split Manufactured Circuits

Abstract

Split manufacturing of integrated circuits was proposed as a strong defense technique against reverse engineering at untrusted foundries. Split manufacturing has been shown to be vulnerable to proximity-based attacks and suitable defenses against these attacks have been proposed. In this paper, we apply an attack against split manufactured circuits based on satisfiability (SAT) solving, without requiring any proximity information. Our method formulates the problem of recovering the hidden signals as a Boolean decryption problem of determining the control signals (keys) of a multiplexer network, determines logical constraints to avoid solutions which could enable cyclic paths through the circuit and reduces the number of these constraints by eliminating redundant constraints. The resulting constrained decryption problem is solved by a satisfiability attack. We demonstrate the effectiveness of the attack on a set of benchmarks. In addition, we discuss a split manufacturing approach to potentially deter the SAT attack.