Verifiable cloud-based variational quantum algorithms

TL;DR

This paper proposes a new protocol for cloud-based variational quantum algorithms that improves verifiability and robustness against channel loss, making quantum cloud computing more secure and practical.

Contribution

It introduces a novel protocol that enhances verifiability and channel loss tolerance for cloud-based VQAs, addressing limitations of previous methods.

Findings

The new protocol achieves verifiability in cloud VQAs.

It demonstrates increased tolerance to channel loss.

The protocol reduces quantum resource requirements.

Abstract

Variational quantum algorithms (VQAs) have shown potential for quantum advantage with noisy intermediate-scale quantum (NISQ) devices for quantum machine learning (QML). However, given the high cost and limited availability of quantum resources, delegating VQAs via cloud networks is a more practical solution for clients with limited quantum capabilities. Recently, Shingu et al.[Physical Review A, 105, 022603 (2022)] proposed a variational secure cloud quantum computing protocol, utilizing ancilla-driven quantum computation (ADQC) for cloud-based VQAs with minimal quantum resource consumption. However, their protocol lacks verifiability, which exposes it to potential malicious behaviors by the server. Additionally, channel loss requires frequent re-delegation as the size of the delegated variational circuit grows, complicating verification due to increased circuit complexity. This paper introduces a new protocol to address these challenges and enhance both verifiability and tolerance to channel loss in cloud-based VQAs.