Binary and Ternary True Random Number Generators Based on Spin Orbit Torque

Abstract

In this work, we have experimentally demonstrated the binary- and ternary-True Random Number Generators (B-TRNG and T-TRNG) based on the stochastic switching characteristics of the nano-scale Ta/CoFeB/MgO heterostructures with perpendicular magnetization anisotropy. For the first time, the random code generation utilizes the spin orbit torque (SOT) induced by current flowing in the heavy metal underneath the CoFeB layer. The 3-XOR post-processed random binary codes have passed the NIST SP800-22 test. Furthermore, the T-TRNG in the same ferromagnetic heterostructure with dual magnetic domains are also demonstrated, which provides a higher security level than its B-TRNG counterpart.