In this paper, we present a reconfigurable Physically Unclonable Functions (PUF) based on the Spin-Orbit-Torque Magnetic Random-Access Memory (SOT-MRAM), which exploits thermal noise as the true dynamic entropy source. Therefore, the MRAM cells could be configured to random final states with stochastic switching mechanism. The proposed PUF is constructed and reconfigured by combining the small-capacity true random number generator (TRNG) and high-reliability secure hash algorithm (SHA-512), realizing the dynamic transformation between SOT-MRAM based last level cache and PUF (In-Cache-MPUF). Thanks to the full reconfigurability and the high endurance of SOT-MRAM, the proposed In-Cache-MPUF can achieve$10^{\textbf {14}}$maximum PUF bits per cell, which has greatly motivated the implementations compared with the traditional weak PUFs utilizing the static entropy source of process variations. The Monte-Carlo simulation results using 40 nm technology and a compact MTJ model show that the proposed PUF has desirable randomness as the digitized bit streams passing all the NIST tests, achieving 50.0428% uniqueness as well as 49.9236% uniformity. It also shows comparable reliability to the state-of-the-art works: a maximum bit error rate of 0.14% and 0.12% at 100 °C and 0.9 V, respectively. In addition, the system level performance is tested and validated by gem5.

With the rapid development of the Internet of Things (IoT) infrastructure, electronic devices are becoming ubiquitous, in which authentication and secure communication are required. As a result, novel hardware security primitives have been developed to overcome the deficiencies of conventional security methods and address the growing security issues. Physical unclonable function (PUF) is an emerging hardware security primitive that plays an important role in authenticity and reliability of integrated circuits (ICs). Spin-transfer torque magne- toresistive random access memory (STT-MRAM) is a promising technology that is dense, fast, non-volatile, highly endurant and energy-efficient. STT-MRAM is considered a promising primitive as it has several intrinsic randomness sources, such as stochastic switching, process variations and statistical read/write failures. This paper proposes a novel hybrid STT-MRAM/complementary metal-oxide semiconductor (CMOS) based reconfigurable arbiter PUF. The functionality of the design is validated by a 28nm CMOS technology and a compact magnetic tunnel junction (MTJ) model. Simulation results show that the proposed PUF has a mean intra-hamming distance (HD) of 0.24%, a mean inter-HD of 51.1% and passes the National Institute of Standards and Technology (NIST) statistical tests.

With low power consumption, fast access speed, high scalability and infinite endurance, spin-transfer torque magnetoresistive random access memory (STT-MRAM) is considered as one of the most promising alternatives to SRAM. However, The performance of STT-MRAM is significantly influenced by several reliability issues, such as process variations and stochastic switching. Most of the reliability analysis of relative circuits are performed at bit-cell and memory level, while that at computer-system level is missing. This paper proposes an efficient framework for performance evaluation of STT-MRAM on computer architecture-level implemented by GEM5+NVMain co-simulator in consideration of the reliability issues. The results show that the overall average latency and energy of STT-MRAM can be up to 5.996% and 20.65% larger than that of the nominal cases in a computer system-level memory architecture taking reliability issues into account. Because reliability issues are considered during the design phase, our framework can provide more accurate performance evaluation and contribute to a higher yield of STT-MRAM based computer systems.

Physical unclonable function (PUF) is considered as a promising hardware security primitive for a variety of applications. Recently, with the rapid development of integrated circuit (IC), the requirement for low complexity, high power efficiency and high performance PUFs become urgent. Moreover, a variety of powerful attack approaches have been carried out to counterfeit PUFs. This paper proposes a novel PUF design by utilizing the spin transfer torque magnetic random-access memory (STT-MRAM). The intrinsic process variation of STT-MRAM is exploited as an entropy source for generating PUF response. The primary performance metrics in terms of reliability, uniformity, uniqueness, and diffuseness of our proposed PUF have been verified, which validate its functionality. In addition, machine learning based modeling attacks are employed to evaluate the security level of proposed STT-MRAM based PUF (MPUF). The statistical results show that MPUF is much more immune to modeling attacks compared with the traditional Arbiter PUF.