Abstract: The power system features numerous nodes and heavy traffic. Current quantum key distribution have insufficient key generation rates to meet the encryption requirements of power system services. This paper proposes a dynamic feedbackbased quantum key adjustment scheme to address the security challenges in power system under limited quantum key resources in crossdomain key pools. The scheme consists of two phases, corresponding to the dynamic adjustment of key pool input and output. The feedback mechanism is applied to maintain equilibrium. During the dynamic adjustment of input, realtime selection and optimization of quantum key distribution protocols are carried out based on environmental factors to improve the realtime input rate of quantum keys. During the dynamic adjustment of output, the allocation and utilization of quantum key resources are settled to maximize the overall security level of data within the sampling time. Feedback on data security is reported to the input phase to ensure that the encryption can reach the predetermined lower limit of overall security level. Experimental results show that the proposed scheme achieves an average gain of 12.59% in overall service security under highsecurityrisk conditions, outperforming conventional methods.

Key words: power system, quantum communication, quantum key distribution, quantum key dynamic adjustment, feedback mechanism

摘要： 电力系统具有站点数量多和业务流量大的特点，当前量子密钥分发设备的密钥生成速率无法满足电力系统的业务加密需求.针对跨域密钥池中量子密钥资源受限条件下电力业务加密的安全性问题，提出一种基于反馈机制的电力系统量子密钥动态调整方案.该方案分为密钥池输入动态调整和密钥池输出动态调整2部分，通过反馈机制维持平衡.输入动态调整根据噪声等环境因素实时选择并优化量子密钥分发协议，提升量子密钥实时输入速率；输出动态调整以最大化采样时间内业务整体安全度为目标，优化量子密钥资源的分配方式和使用方式.输出动态调整完成后，反馈密钥使用信息和业务安全度并再次调整输入，保证实际业务加密可达到预设的整体安全度下限.实验结果表明，采用所提出的量子密钥动态调整方案，在安全风险较高的条件下，业务整体安全度平均增益为12.59%.

关键词: 电力系统, 量子通信, 量子密钥分发, 量子密钥动态调整, 反馈机制