Bit error probability evaluation of RO PUFs

Abstract

Physically unclonable functions (PUFs) are crucial to the implementations of secure key protection and authentication protocol. Ring oscillator PUF (RO PUF) is popular for its nice properties of neat structure. The power of an accurate model to describe the characteristics of a physical system is beyond doubt. However, there are few publications to quantitatively analyze the source of RO PUF’s bit error probability and give out a calculation model for the bit error probability. In this paper, based on the characteristics of RO and the pairwise comparison of different oscillations, we quantitatively describe the factors to affect RO PUF’s bit error rate, including the process variation, sampling interval and temperature. Experiments are conducted to demonstrate the validation of our calculating model. Our work allows the studying of RO PUF’s bit error probability in full detail, and strengthen the evaluation scheme of RO PUF. What’s more, it is an important tool for designers to construct more efficient RO PUF-based systems.