标题： 基于使用诱饵脉冲对抗窃听者光子数分束攻击的量子密钥分发：一种用于性能评估和设计的逐事件损伤枚举方法 显示英文标题

标题： Quantum-Key Distribution using Decoy Pulses to Combat Photon-Number Splitting by Eavesdropper: An Event-by-Event Impairment Enumeration Approach for Performance Evaluation and Design

摘要： 基于量子通信链路的量子密钥分发（QKD）方案通常基于通过光纤传输弱光脉冲，在发送节点和接收节点之间建立一个秘密密钥。 爱丽丝通过与光子相关的光波的偏振或正交分量，向接收者（鲍勃）光学传输一个随机比特流，其中隐含地嵌入了一个秘密密钥。 然而，在上述传输过程中，某些窃听者（厄娃）可能会尝试从光纤链路中截取经过的光子以提取密钥。 在一种流行的QKD方案中，除了信号脉冲外，爱丽丝还会传输一些额外的诱饵脉冲，而厄娃可能会使用光子数分割（PNS）进行窃听。 在一个典型的PNS方案中，（i）带有单光子的光脉冲被厄娃阻挡，（ii）从带有两个光子的光脉冲中，厄娃保留一个光子以执行窃听操作，并将另一个光子重新发送给鲍勃，（iii）所有带有超过两个光子的其他脉冲都会被厄娃重新发送给鲍勃，而不保留任何光子。 已经对这类QKD方案进行了大量的理论研究，通过信息论方法以及计算机仿真和实验研究。 我们提出了一种新颖的逐事件损伤枚举方法，以考虑量子通信链路的物理层，从而对这种QKD方案的整体性能进行分析评估。 所提出的方法使用统计方法在光纤链路的所有可能位置上逐事件监测传播光脉冲的损伤，并提供可实现的密钥生成速率估计，同时确保信号脉冲和诱饵脉冲之间有足够的产量比以检测可能的窃听。 显示英文摘要

摘要： Quantum-key distribution (QKD) schemes employing quantum communication links are typically based on the transmission of weak optical pulses over optical fibers to setup a secret key between the transmitting and receiving nodes. Alice transmits optically a random bit stream to the receiver (Bob) through the photon polarizations or the quadrature components of the lightwaves associated with the photons, with a secret key remaining implicitly embedded therein. However, during the above transmission, some eavesdropper (Eve) might attempt to tap the passing-by photons from the optical fiber links to extract the key. In one of the popular QKD schemes, along with signal pulses, some additional decoy pulses are transmitted by Alice, while Eve might use photon-number splitting (PNS) for eavesdropping. In a typical PNS scheme, (i) the optical pulses with single photon are blocked by Eve, (ii) from the optical pulses with two photons, one photon is retained by Eve to carry out eavesdropping operation and the other is retransmitted to Bob, and (iii) all other pulses with more than two photons are retransmitted by Eve to Bob without retaining any photon from them. Extensive theoretical research has been carried out on such QKD schemes, by employing information-theoretic approach along with computer simulations and experimental studies. We present a novel event-by-event impairment enumeration approach to evaluate the overall performance of one such QKD scheme analytically with due consideration to the physical layer of the quantum communication links. The proposed approach monitors the impairments of the propagating optical pulses event-by-event at all possible locations along the optical fiber link using statistical approach, and provides estimates of the realizable key generation rate, while assuring an adequate yield ratio between signal and decoy pulses for the detection of possible eavesdropping.