LoPher: SAT-Hardened Logic Embedding on Block Ciphers

• Joseth Garcia, Computer Science, University of Delaware

• Satwik Patnaik, Electrical and Computer Engineering, University of Delaware

Hardware security is a crucial aspect of cybersecurity. Unlike software, hardware cannot be easily updated or changed, making it essential to ensure that it is as secure as possible from the outset. One approach to hardware security is logic locking—a design concealment technique used to protect the intellectual property (IP) integrated into modern System-on-Chip (SoC) chips.

Block ciphers, a well-known class of cryptographic algorithms, have been largely unexplored in the context of logic locking. In this project, we re-implemented and evaluated the security of a defense technique that utilizes block ciphers to obscure logic gates. Although this technique holds significant promise for protecting the IP of hardware cores, our analysis shows that some leakage of sensitive information is possible, thereby aiding an attacker to recover parts of the protected design.