Lin Ya-Qian, Wang Meng, Yang Xiu-Qing, Liu Hong-Wei
College of Science, Inner Mongolia University of Technology, Hohhot 010051, China.
China Information Technology Security Evaluation Center, Beijing 100085, China.
Heliyon. 2023 Feb 13;9(2):e13719. doi: 10.1016/j.heliyon.2023.e13719. eCollection 2023 Feb.
Compared with the traditional BB84 protocol, the counterfactual quantum key distribution (QKD) does not rely on any signal travelling in the quantum channel, and therefore can present a security advantage where Eve cannot fully access signal. However, the practical system may be damaged in a scenario where the devices are untrusted. In this paper, we analyze the security of counterfactual QKD in untrusted detectors scenario. We show that the requirement to disclose "which detector clicked" has become the main loophole in all counterfactual QKD versions. An eavesdropping scheme which is similar to the memory attack on device-independent QKD could break its security by exploiting detectors' imperfections. We consider two different counterfactual QKD protocols and analyze their security against this major loophole. One is a modified Noh09 protocol, which would be secure in untrusted detectors context. Another is a variant of counterfactual QKD with high efficiency (Phys. Rev. A 104 (2021) 022424) against a series of detectors side-channel attacks as well as against other attacks that exploit detectors imperfections.
与传统的BB84协议相比，反事实量子密钥分发（QKD）不依赖于任何在量子信道中传输的信号，因此在伊芙（Eve）无法完全获取信号的情况下具有安全优势。然而，在设备不可信的场景中，实际系统可能会受到损害。在本文中，我们分析了在不可信探测器场景下反事实QKD的安全性。我们表明，披露“哪个探测器被触发”的要求已成为所有反事实QKD版本中的主要漏洞。一种类似于对与设备无关的QKD进行记忆攻击的窃听方案，可以通过利用探测器的缺陷来破坏其安全性。我们考虑了两种不同的反事实QKD协议，并分析了它们针对这一主要漏洞的安全性。一种是改进的Noh09协议，在不可信探测器的情况下它是安全的。另一种是具有高效率的反事实QKD变体（《物理评论A》104 (2021) 022424），可抵御一系列探测器侧信道攻击以及利用探测器缺陷的其他攻击。
