AI 中文总结
针对连续变量量子密钥分发系统中收发器带宽失配问题，提出频谱攻击方案，能直接获取原始密钥信息，通过对有滤波操作的系统进行原理验证攻击及实验，验证其可行性，还基于漏洞提出防御策略，弥合理论与实践差距。
AI 中文摘要
连续变量量子密钥分发（CVQKD）因其兼容性和低成本而备受关注。然而，收发器之间存在不同程度的带宽失配，这可能导致携带调制信息的频率成分无法被合法方完全感知。本文识别出由带宽失配导致的实际安全漏洞，并提出相应的频谱攻击方案。该方案与以往利用安全漏洞隐藏截获重发攻击引入的额外噪声的方法不同，能直接获取原始密钥信息且不引入额外干扰。构建了对具有滤波操作的CVQKD系统的原理验证攻击以验证可行性。实验结果表明，若忽略此实际安全漏洞，Eve可获取足够信息使系统不安全。基于所识别的安全漏洞，还提出了相应防御策略。这项工作有助于弥合理论模型与实际实现之间的差距，为实际量子通信系统的防御设计提供参考。
英文摘要
Continuous-variable quantum key distribution (CVQKD) has attracted extensive attention due to its compatibility and low costs. However, bandwidth mismatch exists to varying degrees between the transmitter and receiver. This may prevent frequency components carrying modulation information from being fully perceived by the legitimate party. In this paper, we identify a practical security loophole caused by bandwidth mismatch and propose a corresponding spectral attack scheme. Different from previous approaches that exploit security loopholes to conceal the excess noise introduced by intercept-resend attacks, this scheme can directly obtain raw-key information without introducing additional disturbances. A proof-of-principle attack on a CVQKD system with filtering operation is constructed to verify the feasibility. Experimental results indicate that Eve can obtain enough information to render the system insecure if this practical security loophole is ignored. Based on the identified security loophole, corresponding defense strategies are proposed. This work helps bridge the gap between theoretical models and practical implementations, providing a reference for defense design in practical quantum communication systems.
