A Novel Physical Unclonable Function Based on Hybrid Current Mirror

Intrinsic manufacturing process variations are extensive, unpredictable, and inevitable in modern semiconductor technology. This is advantageously utilized in physically unclonable function (PUF) circuits for enhancing hardware and software security. Among widely-known PUF variants, the Arbiter PUF based on digital building blocks has a regular structure and low hardware footprint; however, it is susceptible to machine learning-based modeling attacks. In this work, we propose a new low-power and reliable PUF, based on the hybrid current mirror inverter (CMI). The proposed PUF circuit exploits the process variation-induced randomness in the CMI circuits to generate instance-specific challenge-response characteristics. The current mirror ensures the stability of the overdrive voltages across all the transistors in the CMI blocks, thereby improving the reliability of the proposed PUF. The PUF circuit was simulated at a 45 nm CMOS technology node, and its major performance metrics were evaluated. The simulation results demonstrated that the proposed PUF has excellent performance metrics while having low hardware and resource footprint. In addition, the proposed PUF demonstrated robustness against machine learning-based model-building attacks.