新型循环差分相移量子密钥分发协议

Novel Round-Robin Differential Phase Shift Quantum Key Distribution

量子密钥分发(QKD)作为一种由量子物理保证的绝对安全的密钥分发引起了广泛的关注。在现有的量子密钥分发协议中,循环差分相移量子密钥分发协议(RRDPS-QKD)因其具有较大的比特错误容限度,在实际应用中具有极大的优势。在循环差分相移量子密钥分发协议基础上,设计一种新型循环差分相移量子密钥分发协议,在接收设备中通过一个开关将接收到的脉冲序列分为两支(定义为奇偶两支路),在奇(偶)路上加入一个随机延时器和一个延时器,既能使接收端接收到的所有脉冲都能参与干涉,提升脉冲序列的利用率,又能使发送端可以连续发送脉冲序列。仿真分析结果和模拟量子密钥分发实验结果表明,新型循环差分相移量子密钥分发协议能够明显增大脉冲序列参与干涉的概率,有效地提升了循环差分相移量子密钥分发协议的安全密钥率。

Quantum key distribution(QKD)is an absolutely secure key distribution guaranteed by quantum physics and has attracted significant attention.Among existing quantum key distribution protocols,the roundrobin differential phase shift quantum key distribution protocol(RRDPSQKD)has significant advantages in practical applications because of its large error tolerance.In this study,a novel roundrobin differential phase shift quantum key distribution protocol is proposed.The received pulse trains are divided into odd and even branches using a switch.A random delay device,followed by a delay device,are added to each branch so that all the pulses from the source can participate in the interference at the receiver,and thus,improve the utilization rate of the pulse trains.The proposed protocol also ensures that the source can transmit the pulse trains continuously.The simulation analysis results and simulation quantum key distribution experimental results show that the proposed protocol can considerably increase the interference probability of the pulse trains and effectively improve the security key rate of the roundrobin differential phase shift quantum key distribution protocol.