True Random Number Generation using Latency Variations of Commercial MRAM Chips

TL;DR

This paper presents a novel true random number generator leveraging the intrinsic stochastic switching behavior of commercial MRAM chips by manipulating write latency, achieving high-speed and robust randomness suitable for practical applications.

Contribution

First system-level implementation of a TRNG using COTS toggle MRAM technology exploiting latency variations for randomness generation.

Findings

Achieves ~22 Mbit/s generation speed.

Passes NIST SP-800-22 randomness tests.

Robust over various operating conditions.

Abstract

The emerging magneto-resistive RAM (MRAM) has considerable potential to become a universal memory technology because of its several advantages: unlimited endurance, lower read/write latency, ultralow-power operation, high-density, and CMOS compatibility, etc. This paper will demonstrate an effective technique to generate random numbers from energy-efficient consumer-off-the-shelf (COTS) MRAM chips. In the proposed scheme, the inherent (intrinsic/extrinsic process variation) stochastic switching behavior of magnetic tunnel junctions (MTJs) is exploited by manipulating the write latency of COTS MRAM chips. This is the first system-level experimental implementation of true random number generator (TRNG) using COTS toggle MRAM technology to the best of our knowledge. The experimental results and subsequent NIST SP-800-22 suite test reveal that the proposed latency-based TRNG is acceptably fast (~22 Mbit/s in the worst case) and robust over a wide range of operating conditions.