A Strong Physically Unclonable Function With >2⁸⁰ CRPs and <1.4% BER Using Passive ReRAM Technology

We experimentally demonstrate a strong physically unclonable function (PUF) circuit featuring >2
⁸⁰
challenge-response pair (CRP) capacity, .1.4% bit-error-rate (BER), and strong resiliency against advanced machine learning (ML) attacks. Similar to our recent work, our design takes advantage of the intrinsic variations in the nonlinear static characteristics and leakage currents of as-fabricated F = 250-nm half-pitch 64 × 64 ReRAM circuits. Passive crossbar circuits with 4F
²
area per crosspoint device and reduced peripheral overhead, not requiring any circuitry for programming, result in an extremely compact design, while low-power consumption is achieved by keeping ReRAM devices in the highly resistive, virgin states. The key contributions of this letter is a novel leakage injection approach using an electrically isolated portion of the crossbar array, which boosts PUF's robustness, and a key-booking scheme, which dramatically improves reliability across a wide temperature range of operation and further increases PUF circuit density by reducing error correcting overheads. The experimental results showed near-ideal functional performance metrics, including 49.55% uniformity, 49.95% diffuseness, and 49.25% uniqueness. The measured response also passed all relevant NIST randomness tests.