Modelling efficient BB84 with applications for medium-range, terrestrial free-space QKD
Modelling efficient BB84 with applications for medium-range, terrestrial free-space QKD
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DOI：
10.1088/1367-2630/ac7f4e
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发表时间：
2022-07-01
影响因子：
3.3
通讯作者：
Oi, Daniel K. L.
中科院分区：
文献类型：
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作者：
Brougham, Thomas;Oi, Daniel K. L.
地面自由空间(FS)量子密钥分发(QKD)非常适合在密集的城市环境中部署。然而，从实验室向商业部署的过渡提出了一些重要的工程和部署问题。在这里，我们研究了使用弱相干脉冲诱饵态协议来实现有效的BB84的这些问题。当协议参数的优化范围由于实际考虑而受到限制时，我们计算不同环境条件下的预期密钥长度。特别是，我们发现，对于固定的接收器基准选择概率，允许发射机根据变化的信道损耗和背景光级别具有不同的基准选择概率可能是有利的。最后，我们研究了脉冲强度不确定性的影响，发现它们可以显著缩短密钥长度。这些结果可用于确定量子密钥分配系统中FS光学元件的损耗预算，并辅助其设计。
Terrestrial free-space (FS) quantum key distribution (QKD) is ideally suited for deployment in dense urban environments. The transition from laboratory to commercial deployment, however, raises a number of important engineering and deployment issues. Here, we investigate these issues for efficient BB84 using a weak coherent pulse-decoy state protocol. We calculate expected key lengths for different environmental conditions and when the scope for optimisation of protocol parameters is restricted due to practical considerations. In particular, we find that for a fixed receiver basis choice probability, it can be advantageous to allow the transmitter to have a different basis choice probability depending on varying channel loss and background light levels. Finally, we examine the effects of pulse intensity uncertainty finding that they can dramatically reduce the key length. These results can be used to determine the loss budget for the FS optics of a QKD systems and assist in their design.