Superlinear threshold detectors in quantum cryptography
Superlinear threshold detectors in quantum cryptography
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DOI：
10.1103/physreva.84.032320
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发表时间：
2011-09-15
影响因子：
2.9
通讯作者：
Leuchs, Gerd
中科院分区：
文献类型：
--
作者：
Lydersen, Lars;Jain, Nitin;Leuchs, Gerd
我们引入了超线性阈值探测器的概念，这是一种如果同时接收多个光子而不是在单独的时间接收多个光子的探测器，它具有更高的探测概率。量子密钥分发系统中的高度超线性门限检测器允许窃听完整的秘密密钥而不会被泄露。在这里，我们概括了检测器控制攻击，并分析了它对具有适度超线性检测器的量子密钥分配系统的性能。我们根据早期发表的数据对超导单光子探测器的超线性进行了量化，并根据我们自己的测量结果对门控雪崩光电二极管探测器的超线性进行了量化。分析表明，无论使用哪种类型的检测器(S)，量子密钥分发系统都容易被窃听。雪崩光电二极管探测器在门的末端变得超线性。对于预计会有很大损失的系统，或者对于没有监测损失的系统，这将允许使用每个脉冲包含少于120个光子的触发脉冲进行窃听。使用接收器入口处的光功率计几乎不可能捕捉到这样的攻击。
We introduce the concept of a superlinear threshold detector, a detector that has a higher probability to detect multiple photons if it receives them simultaneously rather than at separate times. Highly superlinear threshold detectors in quantum key distribution systems allow eavesdropping the full secret key without being revealed. Here, we generalize the detector control attack, and analyze how it performs against quantum key distribution systems with moderately superlinear detectors. We quantify the superlinearity in superconducting single-photon detectors based on earlier published data, and gated avalanche photodiode detectors based on our own measurements. The analysis shows that quantum key distribution systems using detector(s) of either type can be vulnerable to eavesdropping. The avalanche photodiode detector becomes superlinear toward the end of the gate. For systems expecting substantial loss, or for systems not monitoring loss, this would allow eavesdropping using trigger pulses containing less than 120 photons per pulse. Such an attack would be virtually impossible to catch with an optical power meter at the receiver entrance.