面向最小接收器量子密钥分发的抗损失扰动证明
A Loss-Robust Disturbance Certificate for Minimal-Receiver Quantum Key Distribution
浏览论文内容
中文总结 AI 辅助
该研究针对最小接收器量子密钥分发，提出抗损失扰动证明，填补了其零概率误差子集合结构的研究空白，经Qiskit验证可降低QKD硬件成本，推动其在网络边缘应用。
中文摘要 AI 辅助
量子密钥分发（QKD）具备信息论安全性，但针对已部署系统的最具破坏性攻击会利用接收器，其中密钥比特通过一对非完全相同的探测器中哪一个触发来编码。最小接收器由一个可旋转偏振器和一个阈值探测器组成，可消除该攻击面，且单探测器BB84演示已采用采样误差估计；然而，其零概率误差子集合的结构仍未被表征。我们精确表征了该结构，引入了一种确定性不可能事件证明：在理想信道下，设置为与传输态正交的偏振器后的点击概率恰好为零，因此单次出现就是概率为1的扰动见证；且由于损失会消除点击但绝不会产生点击，该证明具有抗损失性。我们证明其在三种偏振态下是可靠但不完备的，并表明四种BB84态可填补该缺口：固定基截获-重发攻击每轮正交回合的理想触发概率为1/4（探测效率η下观测到的概率为η/4），且与截获角度无关。示例有限尺寸预算在η=0.1时，从约62000次传输回合中保留256比特；在实际探测器噪声（每个开启门的q0=10^-6）下，每轮触发在每会话亚百分比的诚实弃权（不执行）概率下保留约12比特证据。核心理想触发概率预测通过已发布的固定随机种子实现在Qiskit电路模拟器上得到数值验证。总体而言，通过为偏振QKD的最小探测器接收器提供结论性的、抗损失的扰动警报，我们的方案降低了安全监控QKD的硬件入门成本，从而以对成本敏感的网络边缘的应用成本促进其采用。
英文摘要
Quantum Key Distribution (QKD) enjoys information-theoretic security, yet the most damaging attacks against deployed systems exploit the receiver, where the key bit is encoded in which one of a pair of never-identical detectors clicks. The minimal receiver, one rotatable polarizer and one threshold detector, removes that attack surface, and single-detector BB84 demonstrations already run sampled error estimation; the structure of its zero-probability error subensemble, however, has remained uncharacterized. We characterize exactly that structure, introducing a deterministic impossible-event certificate: a click behind a polarizer set orthogonal to the transmitted state has probability exactly zero on an ideal channel, so a single occurrence is a probability-one witness of disturbance; and, since loss deletes clicks and never creates them, the certificate is loss-robust. We prove it sound but incomplete over three polarization states, and show that the four BB84 states close the gap: a fixed-basis intercept-resend attack yields an ideal trip probability of $1/4$ per orthogonal round ($η/4$ observed at detection efficiency $η$), independent of the interception angle. An illustrative finite-size budget yields 256 retained bits from $\approx 62{,}000$ transmitted rounds at $η= 0.1$; under realistic detector noise ($q_0 = 10^{-6}$ per opened gate), each trip retains $\approx 12$ bits of evidence at a sub-percent honest false-abort probability per session. The core ideal trip-probability predictions are numerically verified on the Qiskit circuit simulator, via a released, seed-fixed implementation. Overall, by endowing the minimal-detector receiver of polarization QKD with a conclusive, loss-robust disturbance alarm, our solution lowers the hardware entry cost of security-monitored QKD, hence fostering its adoption at the cost-sensitive network edge.
