Continuous-variable quantum key distribution (CV-QKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users in a communication network. However, the practical devices used to implement these systems are intrinsically imperfect, and, as a result, open the door to eavesdropper attacks. In this work, we show the impact of receiver device imperfections on the estimated channel parameters, performance and security of a CV-QKD system. The presented results show that, due to the erroneously estimated channel parameters, non-monitored imbalances can pose a security risk or even reduce the system’s performance. Our results show the importance of monitoring these imbalances and hint at the possibility of compensating for some receiver imbalances by tuning other components.

中文翻译：

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接收器不平衡对连续变量量子密钥分发安全性的影响

连续可变量子密钥分发 (CV-QKD) 提供了一种理论上无条件安全的解决方案，用于在通信网络中的用户之间分发对称密钥。然而，用于实现这些系统的实际设备本质上是不完善的，因此，为窃听者攻击打开了大门。在这项工作中，我们展示了接收器设备缺陷对 CV-QKD 系统的估计信道参数、性能和安全性的影响。所呈现的结果表明，由于错误估计的信道参数，未监控的不平衡会带来安全风险，甚至会降低系统的性能。我们的结果显示了监控这些不平衡的重要性，并暗示了通过调整其他组件来补偿某些接收器不平衡的可能性。