AI 中文总结
该研究提出一种基于时间模式复用、以LM05操作为基础的量子辅助经典通信协议，推导了相关安全上界，分析了性能受实际约束限制的情况。
AI 中文摘要
我们引入并分析了一种量子辅助的经典通信协议，该协议以LM05操作作为构建块，将有限字母表中的符号编码到时间模式上。该协议对对应于消息符号的时间时隙独立应用比特翻转门，从而在并行信道上产生LM05操作的张量积结构。这种张量积结构会产生标准LM05安全性证明未覆盖的集体攻击。我们推导了随机猜测下完整恢复成功概率的理论上界，其中考虑了接收方对丢失光子的50%猜测能力，并强调该上界假设完美的丢失识别。我们表征了预期传输，推导了符号集模式的渐近集体攻击上界，并确定了可组合安全性的开放挑战。该协议不是独立的量子安全直接通信方案，因为经典排序信息需要加密。对于53符号字母表，在零量子比特错误率（QBER）下，乐观的1%成功上界出现在约0.8公里处，当QBER等于0.01时，该距离减小到约0.6公里；实际约束严重限制了其性能。
英文摘要
We analyze a temporal-mode extension of the two-way LM05 quantum communication primitive, in which a message block is encoded into a fixed-weight binary occupation vector (the support) alongside classical ordering information. We demonstrate that applying an independent-slot recovery model to this correlated source is fundamentally inconsistent. For an ideal erasure channel, we derive the exact maximum-a-posteriori (MAP) recovery probability, showing that source-aware decoding outperforms independent guessing by orders of magnitude. We extend this analysis to a realistic threshold-detector model, quantifying the degradation caused by dark counts and inefficiency. Furthermore, we clarify the quantum-classical information split: in the ideal single-photon limit, preparation averaging renders Eve's state independent of the support, yielding zero Holevo information. We establish conditional security bounds using entropic uncertainty relations and identify photon-number-splitting as the primary practical vulnerability. These results provide a rigorous source-aware recovery benchmark and define the physical conditions under which the quantum layer offers a key-consumption advantage over classical constant-weight coding.
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