Quantum key distribution with setting-choice-independently correlated light sources
Quantum key distribution with setting-choice-independently correlated light sources
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DOI：
10.1038/s41534-018-0122-y
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发表时间：
2019-01-23
影响因子：
7.6
通讯作者：
Tamaki, Kiyoshi
中科院分区：
文献类型：
--
作者：
Mizutani, Akihiro;Kato, Go;Tamaki, Kiyoshi
尽管量子密钥分发（QKD）在理论和实验上取得了巨大的进展，但现有的大多数实用QKD系统的安全性尚未得到严格的确定。一个关键的障碍是，几乎所有现有的安全证明都对QKD设备进行了理想的假设。问题是，这样的假设在实验中很难满足，因此如何将这样的安全性证明应用于实际的QKD系统并不明显。幸运的是，测量设备中的任何缺陷和安全漏洞都可以通过测量设备无关的QKD（MDI-QKD）完美地关闭，因此我们只需要考虑如何保护源设备。在源设备的缺陷中，发送脉冲和调制波动之间的相关性是主要问题之一，不幸的是，大多数现有的安全证明没有考虑。本文考虑到这些缺陷，提高了量子密钥分配实现的安全性。具体来说，我们考虑一个设置选择独立的相关性（SCIC）的框架中，发送脉冲可以呈现任意的相关性，但他们是独立的先前的设置选择，如位，基础和强度设置。在SCIC框架下，考虑了发送态的相对相位和强度等主要涨落，为有限密钥体制下的容损QKD协议提供了一个完备的信息论安全性证明.我们证明了安全量子通信的可行性，因此我们的工作是保证实际QKD系统安全性的关键一步。
Despite the enormous theoretical and experimental progress made so far in quantum key distribution (QKD), the security of most existing practical QKD systems is not rigorously established yet. A critical obstacle is that almost all existing security proofs make ideal assumptions on the QKD devices. Problematically, such assumptions are hard to satisfy in the experiments, and therefore it is not obvious how to apply such security proofs to practical QKD systems. Fortunately, any imperfections and security-loopholes in the measurement devices can be perfectly closed by measurement-device-independent QKD (MDI-QKD), and thus we only need to consider how to secure the source devices. Among imperfections in the source devices, correlations between the sending pulses and modulation fluctuations are one of the principal problems, which unfortunately most of the existing security proofs do not consider. In this paper, we take into account these imperfections and enhance the implementation security of QKD. Specifically, we consider a setting-choice-independent correlation (SCIC) framework in which the sending pulses can present arbitrary correlations but they are independent of the previous setting choices such as the bit, the basis and the intensity settings. Within the framework of SCIC, we consider the dominant fluctuations of the sending states, such as the relative phases and the intensities, and provide a self-contained information-theoretic security proof for the loss-tolerant QKD protocol in the finite-key regime. We demonstrate the feasibility of secure quantum communication, and thus our work constitutes a crucial step towards guaranteeing the security of practical QKD systems.