基于信道特征量化的自适应密钥生成方案设计

摘要

针对现有基于信道特征量化的密钥生成方法无法同时保证生成密钥的强度与系统的有效性，表现为密钥熵率低或不一致率高的问题，提出了一种基于信道特征量化的自适应密钥生成方案，利用密钥速率的上界函数曲线近似实际曲线，在保证一致率的前提下提高信道特征的量化精度，增加生成密钥的熵率；在此基础上依据接收导频信号的信噪比选择生成密钥熵率较大的协商方案。仿真结果表明，利用所提方案生成密钥可以保证密钥强度与系统的有效性。%Approaches generating secret keys based on radio channel characteristics can’t guarantee the key length and system efficiency at the same time because of the low entropy rate or high disagreement ratio of keys. An adaptive key distillation scheme based on the quantization of channel state information was designed. An upper bounding function was used as an approximation of the real one to improve the entropy of keys under the constraint of disagreement rate. Based on this, the key agreement scheme resulting in longer keys was selected. Simulation results show that with this scheme, the length of key and efficiency of the system can be guaranteed at the same time.