A New Non-Binary Response Generation Scheme from Physical Unclonable Functions

TL;DR

This paper introduces a novel non-binary response generation scheme for PUFs that enhances key length and reliability by using probability density functions and thresholding, with FPGA validation showing significant improvements.

Contribution

A new non-binary response scheme based on one-probability and thresholding for PUFs, improving key length and simplifying threshold calculation with FPGA validation.

Findings

Significant increase in effective key length.

Feasibility confirmed through FPGA implementation.

Error rates and biases are within acceptable ranges.

Abstract

Physical Unclonable Functions (PUFs) are widely used in key generation, with each PUF cell typically producing one bit of data. To enable the extraction of longer keys, a new non-binary response generation scheme based on the one-probability of PUF bits is proposed. Instead of using PUF bits directly as keys, non-binary responses are first derived by comparing the one-frequency of PUF bits with thresholds that evenly divide the area under the probability density function of the one-probability distribution and then converted to binary keys. To simplify the calculation of these thresholds, a re-scaling process is proposed and the beta distribution is used to model the one-probability distribution. Our FPGA implementation results demonstrate a significant increase in effective key length as opposed to previous works. Finally, we estimate the error rates and biases of the generated keys, and confirm the feasibility of the proposed key generation scheme.