International Association
for Cryptologic Research

Logic locking has emerged as a promising solution against IP piracy and modification by untrusted entities in the integrated circuit design process. However, its security is challenged by boolean satisfiability (SAT) based attacks. Criteria that are critical to SAT attack success on obfuscated circuits includes scan architecture access to the attacker and/or that the circuit under attack is combinational. To address this issue, we propose a dynamically-obfuscated scan chain (DOSC) technique in resisting SAT attack in an obfuscated sequential design by restricting scan access only to authorized users.