Quantum key distribution with simply characterized light sources
Quantum key distribution with simply characterized light sources
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DOI：
10.1038/s41534-019-0194-3
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发表时间：
2019-10-11
影响因子：
7.6
通讯作者：
Koashi, Masato
中科院分区：
文献类型：
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作者：
Mizutani, Akihiro;Sasaki, Toshihiko;Koashi, Masato
为了保证量子密钥分发（QKD）的安全性，QKD协议的安全性证明都对设备进行了假设。通常使用的假设是，例如，由发送器选择的每个随机比特信息被精确地编码在光发射脉冲上，并且脉冲的光子数概率分布是精确已知的。这些施加在光源上的典型假设，例如上述两个是相当强的，并且在实际的QKD系统中很难验证。本文的目标是用较弱的假设取代那些对光源的强假设。在本文中，我们采用差分相移（DPS）QKD协议，并大大降低了对光源的要求，而对于测量单元，可信和光子数分辨探测器的假设。具体地说，我们只假设发射脉冲之间的独立性，真空发射概率从一个选定的位的独立性，和上界的尾部分布函数的总光子数在一个单一的块的脉冲单，两个和三个光子。值得注意的是，不需要其他详细的特性，如相位调制量。我们的安全证明大大放宽了对光源的要求，这为通过简单的设备验证来保证实施安全铺平了道路。
To guarantee the security of quantum key distribution (QKD), security proofs of QKD protocols have assumptions on the devices. Commonly used assumptions are, for example, each random bit information chosen by a sender to be precisely encoded on an optical emitted pulse and the photon-number probability distribution of the pulse to be exactly known. These typical assumptions imposed on light sources such as the above two are rather strong and would be hard to verify in practical QKD systems. The goal of the paper is to replace those strong assumptions on the light sources with weaker ones. In this paper, we adopt the differentialphase-shift (DPS) QKD protocol and drastically mitigate the requirements on light sources, while for the measurement unit, trusted and photon-number-resolving detectors are assumed. Specifically, we only assume the independence among emitted pulses, the independence of the vacuum emission probability from a chosen bit, and upper bounds on the tail distribution function of the total photon number in a single block of pulses for single, two and three photons. Remarkably, no other detailed characterizations, such as the amount of phase modulation, are required. Our security proof significantly relaxes demands for light sources, which paves a route to guarantee implementation security with simple verification of the devices.