Engineering-Oriented Design of Drift-Resilient MTJ Random Number Generator via Hybrid Control Strategies

TL;DR

This paper introduces a drift-resilient MTJ-based true random number generator architecture that combines feedback and pulse modulation, maintaining stable randomness despite environmental and device aging effects.

Contribution

It proposes a novel hybrid control strategy with the Downcalibration-2 scheme for stable, high-quality randomness without external calibration or bit discarding.

Findings

Maintains stable randomness under temperature drift

Achieves high throughput and robustness

Operates with simple digital logic

Abstract

Magnetic Tunnel Junctions (MTJs) have shown great promise as hardware sources for true random number generation (TRNG) due to their intrinsic stochastic switching behavior. However, practical deployment remains challenged by drift in switching probability caused by thermal fluctuations, device aging, and environmental instability. This work presents an engineering-oriented, drift-resilient MTJ-based TRNG architecture, enabled by a hybrid control strategy that combines self-stabilizing feedback with pulse width modulation. A key component is the Downcalibration-2 scheme, which updates the control parameter every two steps using only integer-resolution timing, ensuring excellent statistical quality without requiring bit discarding, pre-characterization, or external calibration. Extensive experimental measurements and numerical simulations demonstrate that this approach maintains stable randomness under dynamic temperature drift, using only simple digital logic. The proposed architecture offers high throughput, robustness, and scalability, making it well-suited for secure hardware applications, embedded systems, and edge computing environments.