ABSTRACT

High-dimensional quantum key distribution (HD-QKD) can higher the secret-key capacity and tolerate more errors. Several HD-QKD experiments have been demonstrated over deployed fibers to show promising future toward high-dimensional quantum communication networks. However, the practical security of HD-QKD systems should be widely considered before large-scale application of HD-QKD systems. In this paper, we focus on the HD-QKD based on the dispersive optics (DO-QKD) with both statistical and intensity fluctuations. For the condition only with statistical fluctuations, we present the parameter estimation based on an improved Chernoff bound. When considering the condition with both statistical and intensity fluctuations, we present the parameter estimation based on Azuma’s inequality. By numerical simulations, we find that the parameter estimation for DO-QKD based on the improved Chernoff bound is tighter than the previous work in terms of the secret-key capacity and the maximum transmission distance. Moreover, we find that intensity fluctuations affect the performance of DO-QKD greatly and the effect on smaller data size is more obvious.

摘要

高维量子密钥分发（HD-QKD）可以提高私钥容量并容忍更多错误。已经在部署的光纤上进行了一些HD-QKD实验，以证明向高维量子通信网络发展的前景广阔。但是，在大规模应用HD-QKD系统之前，应广泛考虑HD-QKD系统的实际安全性。在本文中，我们重点介绍基于色散光学（DO-QKD）的HD-QKD，它具有统计和强度波动。对于仅具有统计波动的条件，我们提出基于改进的Chernoff边界的参数估计。考虑统计和强度波动的情况时，我们提出基于Azuma不等式的参数估计。通过数值模拟 我们发现，基于改进的切尔诺夫边界的DO-QKD参数估计在密钥容量和最大传输距离方面比以前的工作更加严格。此外，我们发现强度波动极大地影响了DO-QKD的性能，并且对较小数据大小的影响更为明显。