A memristor-based unified PUF and TRNG chip with a concealable ability for advanced edge security

Abstract

Security primitives ensure Internet of Things (IoT) security by generating stable keys from physically unclonable functions (PUFs) and unpredictable bitstreams from true random number generators (TRNGs). Considering the restricted resources on IoT motes, a promising design trend is to unify PUF and TRNG by sharing the same entropy source and multiplexing entropy extractor. Here, we report a unified PUF and TRNG chip based on a 28-nanometer embedded memristor with concealable ability. We use the memristor intrinsic FORMING condition variation and read current variation as entropy sources and design a compact on-chip entropy extractor that achieves a high throughput of 41.7 megabits per second with minimal area overhead of 0.291 MF². To prevent PUF data leakage, we developed a concealment method, protecting data when idle and enabling recovery upon demand. Comprehensive testing shows the chip has excellent performance in randomness, reliability, lifetime, and stability, achieving a 3.82-fold throughput improvement over complementary metal-oxide semiconductor–based designs in authentication tasks.