Unbiased sources of true randomness are critical for the successful deployment of stochastic unconventional computing schemes and encryption applications in hardware. Leveraging nanoscale thermal magnetization fluctuations provides an efficient and almost cost-free means of generating truly random bitstreams, distinguishing them from predictable pseudo-random sequences. However, existing approaches that aim to achieve randomness often suffer from bias, leading to significant deviations from equal fractions of 0 and 1 in the bitstreams and compromising their inherent unpredictability. This study presents a hardware approach that capitalizes on the intrinsic balance of phase noise in an oscillator injection locked at twice its natural frequency, leveraging the stability of this naturally balanced physical system. We demonstrate the successful generation of unbiased and truly random bitstreams through extensive experimentation. Our numerical simulations exhibit excellent agreement with the experimental results, confirming the robustness and viability of our approach.
@article{arxiv.2311.11982,
title = {Unbiased Random Number Generation using Injection-Locked Spin-Torque Nano-Oscillators},
author = {Nhat-Tan Phan and Nitin Prasad and Abderrazak Hakam and Ahmed Sidi El Valli and Lorena Anghel and Luana Benetti and Advait Madhavan and Alex S. Jenkins and Ricardo Ferreira and Mark D. Stiles and Ursula Ebels and Philippe Talatchian},
journal= {arXiv preprint arXiv:2311.11982},
year = {2023}
}