R&D: Novel BTBT Erase-Based PUF Generation Method With High Throughput in 3-D NAND Flash Memory

IEEE Transactions on Electron Devices has published an article written by You-Liang Chou, C. C. Cheng, G. W. Wu, Y. W. Chang, W. J. Tsai, T. C. Lu, K. C. Chen, Macronix International Company Ltd, Hsinchu, Taiwan, T. E. Hsieh, T. H. Hou, Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, and C. Y. Lu, Macronix International Company Ltd, Hsinchu, Taiwan.

Abstract: “A novel physical unclonable function (PUF) generation method based on 3-D NAND flash architecture is proposed. We exploit band-to-band tunneling (BTBT) erase operation and the inherent process variations among the bitline (BL)/common-source-line (CSL) junctions in individual nand cell strings to realize a stable PUF. Its outstanding performance sets a new benchmark for flash-based PUFs, featuring high-generation throughput (>100Mb/s) to enhance flexibility in chip authentication and mitigate supply chain attacks. It also demonstrates nearly ideal randomness, strong uniqueness (inter-Hamming distance (inter-HD) ~0.5), and an artificially achieved Hamming weight (HW) = 0.5). Besides, the proposed PUF also exhibits great sustainability of cross-temperature operations, repeated readouts (>10 M times), retention (>500 h/85 ^∘C bake with bit error rate (BER) almost being “zero”), and reproducibility (>1 k P/E cycles).“