Learning Classical Readout Quantum PUFs based on single-qubit gates

TL;DR

This paper analyzes the security of classical readout quantum PUFs based on single-qubit gates, revealing vulnerabilities to modeling attacks and discussing their potential and limitations for device authentication.

Contribution

It formalizes CR-QPUFs within the SQ model and demonstrates their insecurity against modeling attacks, providing insights into their practical viability.

Findings

CR-QPUFs based on single-qubit gates are insecure under SQ access.

A simple polynomial regression attack can forge quantum device signatures.

The attack was successfully tested on real IBM Q quantum machines.

Abstract

Physical Unclonable Functions (PUFs) have been proposed as a way to identify and authenticate electronic devices. Recently, several ideas have been presented that aim to achieve the same for quantum devices. Some of these constructions apply single-qubit gates in order to provide a secure fingerprint of the quantum device. In this work, we formalize the class of Classical Readout Quantum PUFs (CR-QPUFs) using the statistical query (SQ) model and explicitly show insufficient security for CR-QPUFs based on single qubit rotation gates, when the adversary has SQ access to the CR-QPUF. We demonstrate how a malicious party can learn the CR-QPUF characteristics and forge the signature of a quantum device through a modelling attack using a simple regression of low-degree polynomials. The proposed modelling attack was successfully implemented in a real-world scenario on real IBM Q quantum machines. We thoroughly discuss the prospects and problems of CR-QPUFs where quantum device imperfections are used as a secure fingerprint.