一种基于有限密钥和诱骗态的双场量子密钥分发协议

A TWO-FIELD QUANTUM KEY DISTRIBUTION PROTOCOL BASED ON FINITE KEYS AND DECOY STATES

量子保密通信技术为电力业务数据传输提供端到端的信息安全保障,双场量子密钥分发(Twin-field Quantum Key Distribution,TF-QKD)可实现无量子中继器的远程安全通信,但其安全性是基于无限密钥的假设。为解决现实场景中量子密钥有限和光子源不稳定的情形,提出一种基于有限密钥和诱骗态的双场量子密钥分发协议。在协议中采用诱骗态法和无替换的随机抽样法估计相位错误率,并利用Azuma不等式对协议进行安全性分析,验证了在不稳定光子源强度波动下协议的可组合安全性。数值模拟表明所提协议在不稳定光子源强度波动下得到的秘密密钥率可以超过线性密钥率的界线,且当信号脉冲数量较小时,强度波动对协议密钥率有显著影响。

Quantum secure communication technology provides end-to-end information security guarantee for power business data transmission.Twin-field quantum key distribution(TF-QKD) can realize remote secure communication without quantum repeaters.Its security is based on the assumption of unlimited keys.In order to solve the situation of limited quantum keys and unstable photon sources in real scenarios,a two-field quantum key distribution protocol based on finite keys and decoy states is proposed.In the protocol,the decoy state method and the random sampling method without replacement were used to estimate the phase error rate,and the Azuma inequality was used to analyze the security of the protocol,which verified the combinable security of the protocol under the fluctuation of unstable photon source intensity.The numerical simulation shows that the secret key rate of the proposed protocol can exceed the limit of linear key rate under the fluctuation of the intensity of unstable photon source,and when the number of signal pulses is small,the intensity fluctuation has a significant impact on the key rate of the protocol.