针对主动诱骗态方案可能引入边信息的缺点,通过结合旋转不变态,研究了基于标记配对相干态和脉冲位置调制的被动诱骗态测量设备无关量子密钥分配(MDI-QKD)协议。比较了传统MDI-QKD协议、基于旋转不变态的被动诱骗态MDI-QKD协议和具有不同帧长的基于旋转不变态的被动诱骗态MDI-QKD协议的性能优劣。仿真结果表明,引入旋转不变态和脉冲位置调制可以提高密钥生成率和安全传输距离。随着帧长的增加,协议的性能得以改善。因此,在没有强度调制的情况下,该协议避免了光源侧信道的影响,密钥生成率较高。

Aiming at the disadvantage of the active decoy-state scheme to introduce extra information, we investigate the passive decoy-state measurement-device-independent quantum key distribution (MDI-QKD) protocol based on heralded pair coherent states and pulse-position modulation by means of the rotation-invariant photonic state. The performance comparison among the traditional MDI-QKD protocol, the passive decoy-state MDI-QKD protocol based on rotation-invariant photonic states, and the passive decoy-state MDI-QKD protocol based on rotation-invariant photonic states with different frame lengths is conducted. The simulation results show that the key generation rate and the secure transmission distance can be improved if rotation-invariant photonic states and the pulse-position modulation are introduced. Moreover, with the increase of frame length, the performance of the protocol is also improved. Therefore, in the absence of intensity modulation, this protocol can avoid the influence of light side channels and can be used to increase the key generation rate.