Intrinsic Mitigation of the After-Gate Attack in Quantum Key Distribution through Fast-Gated Delayed Detection
Intrinsic Mitigation of the After-Gate Attack in Quantum Key Distribution through Fast-Gated Delayed Detection
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DOI：
10.1103/physrevapplied.12.024050
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发表时间：
2019-08
影响因子：
4.6
通讯作者：
A. Koehler-Sidki;J. Dynes;Amos Martinez;Marco Lucamarini;G. L. Roberts;A. Sharpe;Zhiliang Yuan;A. Shields
中科院分区：
文献类型：
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作者：
A. Koehler-Sidki;J. Dynes;Amos Martinez;Marco Lucamarini;G. L. Roberts;A. Sharpe;Zhiliang Yuan;A. Shields
量子密钥分配（QKD）所承诺的信息理论安全性只要理论模型中的假设与物理实现中的参数相匹配就成立。敏感的单光子探测器的超线性行为代表了这样一种失配，并且可以为阻碍QKD系统安全性的强大攻击铺平道路，一个突出的例子是门后攻击。一个长期的原则是，被困的运营商造成延迟检测可以帮助减轻这种攻击，但尽管经过严格的审查，它仍然在很大程度上未经证实。在这里，我们从物理的角度来处理这个问题，并找到新的证据来支持检测器的安全响应。我们实验研究了两种不同的载流子捕获机制，造成延迟检测快速门控半导体雪崩光电二极管，一个产生的倍增层，其他从吸收和电荷层之间的异质结界面。捕获的载流子的释放增加了在典型的QKD安全阈值之上的后门攻击下测量的量子比特错误率，从而有利于检测器的固有安全性。这是避免QKD系统的量子黑客攻击的重要一步。
The information theoretic security promised by quantum key distribution (QKD) holds as long as the assumptions in the theoretical model match the parameters in the physical implementation. The superlinear behaviour of sensitive single-photon detectors represents one such mismatch and can pave the way to powerful attacks hindering the security of QKD systems, a prominent example being the after-gate attack. A longstanding tenet is that trapped carriers causing delayed detection can help mitigate this attack, but despite intensive scrutiny, it remains largely unproven. Here we approach this problem from a physical perspective and find new evidence to support a detector's secure response. We experimentally investigate two different carrier trapping mechanisms causing delayed detection in fast-gated semiconductor avalanche photodiodes, one arising from the multiplication layer, the other from the heterojunction interface between absorption and charge layers. The release of trapped carriers increases the quantum bit error rate measured under the after-gate attack above the typical QKD security threshold, thus favouring the detector's inherent security. This represents a significant step to avert quantum hacking of QKD systems.