A Wide-Range V ariation-Resilient Physically Unclonable Function in 28 nm Zhen-Y u Liang , Hao-Hsuan Wei, and Tsung-Te Liu

Abstract

This article presents a wide-range, variation- resilient physically unclonable function (PUF) to provide a reliable security primitive solution. The proposed ring oscillator- based PUF employs several stabilization techniques to maintain robustness under environmental variations. The proposed PUF design uses a delay cell topology with an adjusted signal slope to amplify the impact of device variability on delay mismatch. More- over, an online calibration system that extracts in situ PUF delay information and re-configures stage interconnects is employed to further enlarge frequency mismatch and improve stability. Measurement results from a pro totype fabricated in a 28-nm CMOS technology show that the proposed PUF design achieves a highly stable performance over a wide range of operating conditions, with a worst case bit error rate (BER) of 0.55% across 0.4–1.3 V and −40 to 125 ◦C. The measured BER sensitivities to supply voltage (0.0546%/0.1 V) and temperature (0.0052%/10◦C) demonstrate the stability improvements of 2.38 and 28.84 times, respectively, when co mpared with the state-of-the-art results.