Quantum digital signature (QDS) guarantee the unforgeability, nonrepudiation and transferability of signature messages with information-theoretical security, and hence has attracted much attention recently. However, most previous implementations of QDS showed relatively low signature rates or/and short transmission distance. In this paper, we report a proof-of-principle phase-encoding QDS demonstration using only one decoy state. Firstly, such method avoids the modulation of vacuum state, thus reducing experimental complexity and random number consumption. Moreover, incorporating with low-loss asymmetric Mach-Zehnder interferometers and real-time polarization calibration technique, we have successfully achieved higher signature rate, e.g., 0.98 bit/s at 103 km, and to date a record-breaking transmission distance over 280-km installed fibers. Our work represents a significant step towards real-world applications of QDS.
@article{arxiv.2003.00420,
title = {280-km experimental demonstration of quantum digital signature with one decoy state},
author = {Hua-Jian Ding and Jing-Jing Chen and Liang Ji and Xing-Yu Zhou and Chun-Hui Zhang and Chun-Mei Zhang and Qin Wang},
journal= {arXiv preprint arXiv:2003.00420},
year = {2020}
}