AI 中文总结
针对时间-bin编码QKD协议因干涉仪轮次间相干性阻碍安全性证明应用的问题，通过丢弃Bob测量数据中敏感探测器结果恢复IID结构，提升密钥率且无需限制Eve攻击。
AI 中文摘要
量子密钥分发（QKD）的许多安全性证明要求Bob的测量在协议轮次间具有张量积结构，部分技术还要求更强的独立同分布（IID）条件。时间-bin编码协议通常依赖干涉仪，其探测器结果取决于相邻轮次光模式间的干涉，阻碍了此类证明的直接应用。我们表明，对Bob的测量数据进行经典后处理——具体而言，丢弃对轮次间相干性敏感的探测器结果——足以恢复乘积测量正算子值测度（POVM）（若每轮使用相同的单轮设置，该POVM即为IID）。将此方法应用于马赫-曾德尔干涉仪和COW探测设置的IID变体，可消除先前分析中为建立测量POVM的张量积结构引入的额外真空脉冲，在不限制Eve攻击的情况下恢复更高的密钥率。
英文摘要
Many security proofs for quantum key distribution (QKD) require Bob's measurement to have a tensor-product structure across protocol rounds, with some techniques requiring the stronger independent-and-identically-distributed (IID) condition. Time-bin encoded protocols often rely on interferometers whose detector outcomes depend on the interference between optical modes from neighbouring rounds, obstructing the direct application of such proofs. We show that classical post-processing of Bob's measurement data --- specifically, discarding the outcomes of detectors sensitive to inter-round coherence --- is sufficient to recover a product measurement positive operator-valued measure (POVM) (which is IID when the same single-round setup is used in every round). Applied to the Mach-Zehnder interferometer and the IID variant of the COW detection setup, this removes the need for the additional vacuum pulse introduced in prior analyses to establish tensor product structure of the measurement POVM, recovering better key rates without placing any restriction on Eve's attack.
