Strong subthreshold current array PUF with 265 challenge-response pairs resilient to machine learning attacks in 130nm CMOS

This paper presents a strong silicon physically unclonable function (PUF) immune to machine learning (ML) attacks. The PUF, termed the subthreshold current array (SCA) PUF, is composed of a pair of two-dimensional transistor arrays and a low-offset comparator. The fabricated PUF chip allows 265 challenge-response pairs (CRPs) and achieves high reliability with average bit error rate (BER) of 5.8% for temperatures −20 to 80°C and Vdd + 10%. The calibration-based CRPs filtering method effectively improves BER to 2.6% with a 10% loss of CRPs. When subjected to ML attacks, the PUF shows resilience that is 100X higher than known alternatives, with negligible loss in PUF unpredictability.