Performance Analysis of Physically Unclonable Function Based on Voltage Divider Arrays

Abstract

A Physical Unclonable Function (PUF) is a chip-specific random function in which security primitives rely on the inherent randomness of integrated circuit fabrication. It can be used for chip authentication or identification and generation of the key. The most of the PUFs uses the delay to generate set of responses, however, because of linear separability of the response function it results in delay along circuit paths, hence, they are vulnerable to various kind of attacks. In this paper, a new physical Unclonable function is proposed that uses the concept of mismatch between MOSFETs arranged in a voltage divider configuration. All the transistors are subjected to stochastic variability, and they are operated in the subthreshold region. The random binary output is generated by comparing the analog voltages produced by identical arrays. The introduced PUF circuit is simulated using 45 nm Predictive Technology Models (PTM) in HSpice. The voltage divider array-based PUF demonstrates very good characteristics compare to its counterpart methods. The average inter-class HD (a measure of uniqueness) and average intra-class HD (a measure of response stability) are found to be 49.7% and 1.39% respectively.