A Voltage-Controlled Magnetic Anisotropy based True Random Number Generator

Abstract

An emerging nanodevice called voltage controlled magnetic anisotropy magnetic tunnel junction (VCMA-MTJ) exhibits stochastic behavior that can be taken advantage of to produce random numbers at low power, low area, and high speed. In this paper, a 40MHz 104fJ/bit true random number generator (tRNG) was designed that works by applying 1V pulses to the VCMA-MTJ and then reading the resultant state, achieving 6800x the throughput of the most energy-efficient MTJ-based tRNG module designed for security while only consuming 5.21x more energy per bit. However, VCMA-MTJ based tRNG was also found to be very sensitive to variations in free-layer thickness, which can be solved by trading off an 8x increase in area and energy consumption.