量子密钥分配协议的无条件安全性建立在理想的量子设备、经典设备和随机数的假设下。实际系统与理想协议存在一定的差异性,这种差异性可能被窃听者利用,从而导致系统的不安全。利用分束器的分束比具有波长相关特性, 窃听者可以采取波长攻击控制接收端测量基矢的选择。基于基矢选择的随机性偏差参数,给出分束器波长相关性的定量刻画方法。进一步利用纠缠提纯安全性分析技术,分析了量子密钥分配系统在波长攻击下的安全性,给出了不同随机性偏差参数下的安全密钥率公式。

The unconditional security of quantum key distribution protocols is based on the assumption of ideal quantum devices, classical devices and random numbers. However, there are some differences between the actual system and the ideal protocol, which may be controlled by the eavesdropper to attack the practical quantum key distribution system. The realistic beam splitter has a wavelength-dependent property, which can be exploited by the eavesdropper to control the measurement basis selection. By proposing the randomness deviation parameters about the measurement basis selection, the wavelength-dependent property can be effectively estimated. More precisely, security of quantum key distribution with wavelength attack is analyzed by utilizing the entanglement distillation and purification technology, and the security key rate is given with different randomness deviation parameters.