Stochastic Insulator-to-Metal Phase Transition-Based True Random Number Generator

An oscillator-based true random number generator (TRNG) is experimentally demonstrated by exploiting inherently stochastic threshold switching in the insulator-to-metal transition (IMT) in vanadium dioxide. Through experimentation and modeling, we show that the origin of stochasticity arises from small perturbations in the nanoscale domain structure, which are then subsequently amplified through a positive feedback process. Within a 1T1R oscillator, the stochastic cycle-to-cycle variations in the IMT trigger voltage result in random timing jitter, which is harnessed for a TRNG. The randomness of the IMT TRNG output is validated using the NIST SP800-22 statistical test.