Security primitives (PUF and TRNG) with STT-MRAM

Abstract

The rapid development of low power, high density, high performance SoCs has pushed the embedded memories to their limits and opened the field to the development of emerging memory technologies. The Spin-Transfer-Torque Magnetic Random Access Memory (STT-MRAM) has emerged as a promising choice for embedded memories due to its reduced read/write latency and high CMOS integration capability. Inner properties of STT-MRAMs make them suitable for the implementation of basic security primitives such Physically Unclonable Functions (PUFs) and True Random Number Generators (TRNGs). PUFs are emerging primitives used to implement low-cost device authentication and secure secret key generation. On the other hand, TRNGs generate random numbers from a physical process. We will show how it is possible to exploit (i) the high variability affecting the electrical resistance of the magnetic device to build a robust, unclonable and unpredictable PUF, and (ii) the stochastic nature of the write operation in the magnetic device to generate randomly distributed numbers.