In theory, quantum key distribution (QKD) offers information-theoretic security. In practice, however, it does not due to the discrepancies between the assumptions used in the security proofs and the behavior of the real apparatuses. Recent years have witnessed a tremendous effort to fill the gap, but the treatment of correlations among pulses has remained a major elusive problem. Here, we close this gap by introducing a simple yet general method to prove the security of QKD with arbitrarily long-range pulse correlations. Our method is compatible with those security proofs that accommodate all the other typical device imperfections, thus paving the way toward achieving implementation security in QKD with arbitrary flawed devices. Moreover, we introduce a new framework for security proofs, which we call the reference technique. This framework includes existing security proofs as special cases, and it can be widely applied to a number of QKD protocols.

理论上，量子密钥分发 (QKD) 提供信息论安全性。然而，在实践中，这并不是由于安全证明中使用的假设与真实设备的行为之间存在差异。近年来，人们为填补这一空白付出了巨大努力，但脉冲之间相关性的处理仍然是一个难以捉摸的主要问题。在这里，我们通过引入一种简单而通用的方法来证明具有任意远程脉冲相关性的 QKD 的安全性，从而缩小了这一差距。我们的方法与那些适应所有其他典型设备缺陷的安全证明兼容，从而为实现具有任意缺陷设备的 QKD 实现安全性铺平了道路。此外，我们引入了一个新的安全证明框架，我们称之为参考技术。