The performance of quantum key distribution (QKD) is severely limited by multiphoton emissions, due to the photon-number-splitting attack. The most efficient solution, the decoy-state method, requires that the phases of all transmitted pulses are independent and uniformly random. In practice, however, these phases are often correlated, especially in high-speed systems, which opens a security loophole. Here, we address this pressing problem by providing a security proof for decoy-state QKD with correlated phases that offers key rates close to the ideal scenario. Our work paves the way towards high-performance secure QKD with practical laser sources, and may have applications beyond QKD.

中文翻译：

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不完美相位随机化的量子密钥分配的安全性

由于光子数分裂攻击，量子密钥分发（QKD）的性能受到多光子发射的严重限制。最有效的解决方案是诱饵状态方法，要求所有发射脉冲的相位是独立的且均匀随机的。然而，在实践中，这些阶段通常是相关的，尤其是在高速系统中，这会造成安全漏洞。在这里，我们通过提供具有相关相位的诱饵状态 QKD 的安全证明来解决这个紧迫的问题，该证明提供接近理想场景的密钥速率。我们的工作为使用实用激光源实现高性能安全 QKD 铺平了道路，并且可能具有 QKD 之外的应用。