Split manufacturing of integrated circuits reduces vulnerabilities introduced by an untrusted foundry by manufacturing only a part of design at an untrusted high-end foundry and the remaining part at a trusted low-end foundry. Unfortunately, a naive spilt manufacturing alone does not ensure security. An attacker can use proximity attack to undermine the security offered by split manufacturing. However, this attack is applicable only to hierarchical designs. We propose a physical attack model for split manufacturing for industry-standard/ relevant flattened designs. Our attack uses heuristics of physical design tools, which outperform previous attack. We also develop a logic-aware physical attack considering logic redundancy, which identifies incorrect connections effectively. The effectiveness of proposed techniques is demonstrated by simulations on benchmark circuits. Our attack success rate is ~10x that of the proximity attack; our attack predicts 80% of the missing BEOL connections correctly, while the proximity attack predicts only 8% for flattened designs.
