A reconfigurable MRAM PUF with high reliability

Abstract

Physical unclonable function (PUF) has been increasingly applied in the Internet of Things (IoT) fields due to its high security. With the emergence of novel devices, magnetoresistive random access memory (MRAM)-based PUF technology offers excellent energy efficiency and integration density. However, it falls short in terms of response reliability. To address this issue, in this paper, we propose a high-reliability reconfigurable MRAM PUF. First, we propose a novel reconfigurable PUF cell based on the characteristics of MRAM devices. Then, we introduce a sleep mode to reduce the power consumption of PUF. Moreover, we propose a resistance configuration strategy in conjunction with the configurable features of MRAM, which further enhances reliability without increasing hardware overhead. The design is simulated and tested in the SMIC 40 nm process. Experimental results demonstrate that the proposed PUF has a uniqueness of 50.02% and a uniformity of 49.98%, both of which are close to the ideal values. Finally, the bit error rate (BER) is less than 2.2% under temperatures of −40 $\sim$ 120 °C and voltages of 0.7 $\sim$ 1.4 V, which effectively improves the reliability.