Asynchronous measurement-device-independent quantum digital signatures

TL;DR

This paper introduces an asynchronous measurement-device-independent quantum digital signature protocol that enhances security against detector attacks and improves transmission distance and efficiency for quantum networks.

Contribution

It proposes a novel asynchronous MDI-QDS protocol combining two-photon interference and universal hashing, significantly improving performance over previous schemes.

Findings

Achieves several orders of magnitude performance improvement.

Doubles transmission distance for multi-bit messages.

Provides practical protocol for large-scale quantum networks.

Abstract

Quantum digital signatures (QDSs), which distribute and measure quantum states by key generation protocols and then sign messages via classical data processing, are a key area of interest in quantum cryptography. However, the practical implementation of a QDS network has many challenges, including complex interference technical requirements, linear channel loss of quantum state transmission, and potential side-channel attacks on detectors. Here, we propose an asynchronous measurement-device-independent (MDI) QDS protocol with asynchronous two-photon interference strategy and one-time universal hashing method. The two-photon interference approach protects our protocol against all detector side-channel attacks and relaxes the difficulty of experiment implementation, while the asynchronous strategy effectively reduces the equivalent channel loss to its square root. Compared to previous MDI-QDS schemes, our protocol shows several orders of magnitude performance improvements and doubling of transmission distance when processing multi-bit messages. Our findings present an efficient and practical MDI-QDS scheme, paving the way for large-scale data processing with non-repudiation in quantum networks.