Environmental-Variation-Tolerant Magnetic Tunnel Junction-Based Physical Unclonable Function Cell With Auto Write-Back Technique
Byungkyu Song, Sehee Lim, Seung H. Kang, Seong‐Ook Jung
Abstract
Recently, with the increase in popularity of Internet of Things (IoT) devices, cryptographic protection techniques have become necessary for high-security applications. In general, IoT devices have strict power and area constraints. Thus, use of a physical unclonable function (PUF), which can generate a secret key at low cost, can be advantageous for high-security IoT devices. This paper presents a novel environmental-variation-tolerant (EVT) magnetic tunnel junction (MTJ)-based PUF that has a small area, high randomness, and low bit error rate (BER) compared to previous PUFs. The simulation results obtained using industry-compatible 65-nm model parameters indicate that the proposed PUF exhibits an inter-chip Hamming distance of 0.4901 and entropy of 0.9997, which proves the randomness of the PUF response. In addition, the proposed PUF exhibits the lowest BER across a wide voltage range (0.9 V-1.3 V) and temperature range (-25 °C - 75 °C) compared with previous PUFs.