Xue Ke, Shen Zhigang, Zhao Shengmei, Mao Qianping
Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210003, China.
Key Lab of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, Nanjing 210003, China.
Entropy (Basel). 2022 May 8;24(5):662. doi: 10.3390/e24050662.
Twin-field quantum key distribution (TF-QKD) has attracted considerable attention because it can exceed the basic rate-distance limit without quantum repeaters. Its variant protocol, sending or not-sending quantum key distribution (SNS-QKD), not only fixes the security vulnerability of TF-QKD, but also can tolerate large misalignment errors. However, the current SNS-QKD protocol is based on the active decoy-state method, which may lead to side channel information leakage when multiple light intensities are modulated in practice. In this work, we propose a passive decoy-state SNS-QKD protocol to further enhance the security of SNS-QKD. Numerical simulation results show that the protocol not only improves the security in source, but also retains the advantages of tolerating large misalignment errors. Therefore, it may provide further guidance for the practical application of SNS-QKD.
双场量子密钥分发（TF-QKD）因其无需量子中继器就能突破基本的速率-距离限制而备受关注。其变体协议，即发送或不发送量子密钥分发（SNS-QKD），不仅修复了TF-QKD的安全漏洞，还能容忍较大的对准误差。然而，当前的SNS-QKD协议基于主动诱骗态方法，在实际中调制多个光强时可能导致边信道信息泄露。在这项工作中，我们提出了一种被动诱骗态SNS-QKD协议，以进一步增强SNS-QKD的安全性。数值模拟结果表明，该协议不仅提高了光源安全性，还保留了容忍较大对准误差的优点。因此，它可能为SNS-QKD的实际应用提供进一步指导。
