Dynamic attenuation scheme in measurement-device-independent quantum key distribution over turbulent channels
Dynamic attenuation scheme in measurement-device-independent quantum key distribution over turbulent channels
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DOI：
10.1103/physreva.106.032405
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发表时间：
2022-04
影响因子：
2.9
通讯作者：
B. J. Rollick;G. Siopsis;B. Qi
中科院分区：
文献类型：
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作者：
B. J. Rollick;G. Siopsis;B. Qi
与测量设备无关的量子密钥分发（MDI QKD）消除了所有的探测器侧信道，在实践中具有很高的安全性。然而，在自由空间信道上进行MDI QKD是具有挑战性的。最大的罪魁祸首之一是两个独立湍流通道的透射率不匹配，导致Hong-Ou-Mandel可见度降低，从而降低了密钥率。在这里，我们介绍了一种动态衰减方案，通过将每个用户的明亮光脉冲传输到测量设备，实时监测两个通道中每个通道的透射率。根据测量的通道透过率，在测量装置的低损耗通道上引入适当的衰减量。我们的仿真结果表明，QKD性能有了显著提高，特别是在使用短原始密钥时。
Measurement-device-independent quantum key distribution (MDI QKD) offers great security in practice because it removes all detector side channels. However, conducting MDI QKD over free-space channels is challenging. One of the largest culprits is the mismatched transmittance of the two independent turbulent channels causing a reduced Hong-Ou-Mandel visibility and thus a lower secret key rate. Here we introduce a dynamic attenuation scheme, where the transmittance of each of the two channels is monitored in real time by transmitting bright light pulses from each users to the measurement device. Based on the measured channel transmittance, a suitable amount of attenuation is introduced to the low-loss channel at the measurement device. Our simulation results show a significant improvement of QKD performance, especially when using short raw keys.