A High-Speed TiN/LiSiOx/Pt Memristor Array for True Random Number Generation and Secure Image Encryption

Abstract

With the increasing demand for secure IoT communications, memristor-based true random number generators (TRNGs) provide promising hardware security solutions. Here, a TiN/LiSiOx/Pt memristor array is demonstrated as an intrinsic entropy source for TRNG applications. The device exhibits stochastic resistive switching with intrinsic set and reset transition times of 45 ns and 36 ns, respectively. Based on this device characteristic, a compact TRNG circuit is implemented, achieving a maximum measured end-to-end throughput of 4.5 Mb/s. A 1 Mbit raw bitstream without algorithmic post-processing is directly collected and evaluated using autocorrelation analysis, Hamming analysis, NIST SP 800-22 statistical tests, and NIST SP 800-90B non-IID entropy estimation. The generated random bits achieve a conservative min-entropy of 0.994 bit per raw bit. Furthermore, SHA-256-conditioned random keys generated from the TRNG are applied to AES-128 image encryption, demonstrating effective information concealment and favorable statistical characteristics. These results demonstrate the potential of TiN/LiSiOx/Pt memristors for high-speed and secure cryptographic application.