Decoy state semi-quantum key distribution
Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Information and Optoelectronic Science and Engineering, South China Normal University, 510006, Guangzhou, China
2 Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, 510006, Guangzhou, China
3 Department of Optoelectronic Engineering, Jinan University, 510632, Guangzhou, China
Accepted: 18 May 2023
Published online: 31 May 2023
Semi-quantum key distribution describes a system in which a fully quantum user and classical user perform key distribution. The main advantage of key distribution is its security. Owing to the bottlenecks of existing technology, highly attenuated lasers and threshold detectors are required for semi-quantum key distribution; however, these components make semi-quantum key distribution susceptible to eavesdroppers. Our previous study presented the first semi-quantum key distribution experiment and verified the feasibility of the mirror protocol in 2021. Herein, we first build a semi-quantum key distribution channel model and use Gottesman-Lo-Lütkenhaus-Preskill theory to evaluate its safety performance in the case of a quasi-single photon source. Moreover, we determine that an eavesdropper can steal all information through the photon-number-splitting attack without being detected. Therefore, we add decoy states to the semi-quantum key distribution to estimate the furthest transmission distance and secure bit rate under asymptotic conditions. Semi-quantum key distribution can still be achieved safely with highly attenuated lasers and threshold detectors in 150 km.
Key words: Semi-quantum key distribution / Channel model / Photon-number-splitting attack / Decoy state
© The Author(s) 2023
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.