cronokirby

(2026-02) Multipath PA-PUFs generate all Boolean functions

2026-02-21

Abstract

In this paper, we propose a generalized model of Priority Arbiter-based Physical Unclonable Function (PA-PUF) with an arbitrary number of paths inside each switch. We first develop a mathematical model for this generalized model. Experimentally, we observed that the class of Boolean functions generated from our model of PA-PUF increases proportionally with the number of paths inside each switch, and that motivated us to attempt one of the open challenges proposed by Kansal et al. [DAM 2024]. We first show that the set of Boolean functions generated from ii-length PA-PUF with (i+1)(i+1) number of paths is a proper super set of the set of Boolean functions generated from ii-length PA-PUF with ii number of paths. Based upon that, we show in our main result that we need at least (n+1)(n+1) numbers of paths inside each switch of an nn-length PA-PUF to generate all the Boolean functions involving nn-number of variables. Furthermore, we performed significant software and hardware experimentations to assess the resilience of our model against machine learning based modeling attacks.