Patterning-effect mitigating intensity modulator for secure decoy-state quantum key distribution.
Patterning-effect mitigating intensity modulator for secure decoy-state quantum key distribution.
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DOI：
10.1364/ol.43.005110
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发表时间：
2018-07
期刊：
影响因子：
3.6
通讯作者：
G. L. Roberts;M. Pittaluga;M. Minder;Marco Lucamarini;J. Dynes;Z. Yuan;A. Shields
中科院分区：
文献类型：
--
作者：
G. L. Roberts;M. Pittaluga;M. Minder;Marco Lucamarini;J. Dynes;Z. Yuan;A. Shields
量子密钥分发（QKD）是一种允许两个用户安全地交换加密密钥的技术。诱饵状态技术增强了该技术，确保密钥可以在信息理论安全的情况下以高比特率长距离共享。然而，在实现中的不完善，被称为边信道，威胁到实际QKD协议的完美安全性。高速率诱饵态QKD系统需要强度调制器，尽管这些调制器不稳定并且可以显示脉冲强度取决于前一个脉冲的侧通道。在这里，我们证明了上级实用性的可调消光比Sagnac为基础的强度调制器（IM）的实际QKD系统。选择低消光比的能力，以及Sagnac干涉仪对DC漂移的免疫力，确保随机诱饵状态QKD图案可以忠实地再现，同时减轻图案化效应。Sagnac干涉仪的固有稳定性还确保调制器输出不会随时间漂移。
Quantum key distribution (QKD) is a technology that allows two users to exchange cryptographic keys securely. The decoy state technique enhances the technology, ensuring keys can be shared at high bit rates over long distances with information theoretic security. However, imperfections in the implementation, known as side-channels, threaten the perfect security of practical QKD protocols. Intensity modulators are required for high-rate decoy-state QKD systems, although these are unstable and can display a side channel where the intensity of a pulse is dependent on the previous pulse. Here we demonstrate the superior practicality of a tunable extinction ratio Sagnac-based intensity modulator (IM) for practical QKD systems. The ability to select low extinction ratios, alongside the immunity of Sagnac interferometers to DC drifts, ensures that random decoy state QKD patterns can be faithfully reproduced with the patterning effects mitigated. The inherent stability of Sagnac interferometers also ensures that the modulator output does not wander over time.