A Novel BTBT Erase-Based PUF Generation Method With High Throughput in a 3-D _NAND Flash Memory

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 (>100 Mb/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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup>C bake with bit error rate (BER) almost being “zero”), and reproducibility (>1 k P/E cycles).