Highly Reliable RRAM-Based Physical Unclonable Function With Auto-Write Technique

Physical unclonable functions (PUFs) have attracted significant attention for high-security applications, particularly in the Internet of Things (IoT). While resistive random access memory (RRAM)-based PUF technology offers excellent energy efficiency and integration density, its reliability remains a major challenge. This work proposes a highly reliable RRAM-based PUF that utilizes the 4T2R cross-coupled PUF cell to extract the response. Additionally, an automatic write-back technique is introduced to enhance the initial resistance mismatch in RRAM, thereby improving the PUF reliability. Experimental results demonstrate that the proposed PUF achieves outstanding performance, with near-ideal uniqueness (50.02%), uniformity (50.11%), and robust randomness (passing NIST 800-22 tests). The design exhibits robust reliability across a wide operating range (from$- 40~^{\circ }$C to$120~^{\circ }$C and 0.7 to 1.4 V), achieving a bit error rate (BER) of$\lt 4.89\times 10^{-7}$. Furthermore, the energy consumption per bit is optimized to 4.8 fJ at 1.1 V,$25~^{\circ }$C, showing its suitability for energy-constrained applications.