A highly reliable FPGA-based RO PUF with enhanced challenge response pairs resilient to modeling attacks

Abstract

Ring oscillators based physical unclonable functions (RO PUF) is a classical FPGA-friendly Weak PUF structure with better performance, but it can only produce limited challenge-response pairs (CRPs) with lack reliability. This paper proposes a new Strong RO PUF structure with highly reliability and enhanced challenge response pairs resilient to modeling attacks. It divides 2N RO rings into two groups and compares their cumulative frequency under the control of the N-bit challenge to generate 2^N CRPs. The reliability of each bit PUF responses is tested and marked in real time, and a highly reliable anti-fuse PUF structure is introduced to fuzzify the CRPs. FPGA verification results show that this bit self-test RO PUF (BST-RPUF) has a uniformity of 46.78% and a uniqueness of 48.64%, and the bit error rate of the marked reliable responses can be less than 10^-9.