One Trillion True Random Numbers Generated with FPGA-actuated Magnetic Tunnel Junction

Random numbers are crucial in a wide range of applications, from encryption to Monte Carlo simulations. We have recently shown that perpendicular nanopillar magnetic tunnel junctions (pMTJs) activated with short (nanosecond) pulses can generate truly random bits [1]. Here, we significantly accelerate the true random number generation (TRNG) of our stochastic activated MTJs (SMART-MTJs [1]) using Field Programmable Gate Arrays (FPGAs). Our previous experiments used an expensive arbitrary waveform generator (AWG) and a relatively slow (100kHz) analog-to-digital converter (ADC). Our advancement is consolidating the AWG and ADC functions into a low-cost FPGA with a custom-designed daughterboard that provides analog pulses and rapidly reads the junction resistance. With this approach, we produce TRNG at 5MHz, three orders of magnitude faster and with far lower cost instrumentation than our previous method. This has enabled us to rapidly generate over 10^12 random bits that pass the NIST Statistical Test Suite for randomness with only one XOR operation. Increasing the rate of TRNG provides the opportunity to apply the longer SMART bitstream to Monte Carlo simulations, potentially enhancing their accuracy.