基于等效信道的物理层认证和密钥分发机制

Physical-layer authentication and key distribution mechanism based on equivalent channel

现有基于无线信道特征的物理层安全方法通过检测发送方的导频信号实现身份认证,易出现漏检.本文提出基于等效信道的物理层认证及密钥分发机制,利用多个时隙的信道特征对任意密钥进行加密传输建立等效信道,将信道特征的差异映射为传输畸变.依据密钥传输的正确性判断收发两端信道特征互信息的大小,从而在完成密钥的分发的同时实现发端身份认证.分析及仿真说明该机制密钥分发性能与现有方法相当,同时可以在不同空域信道相关性很强的情况下识别出窃听者的攻击.

The authentication of transmitting terminal in present physical-layer security method based on wire- less channel character is implemented by checking the pilot signal sent by it, and missing detection often happens. A new kind of physical-layer authentication and key distribution mechanism based on equivalent channel is pre- sented. The equivalent channel is built by encrypting keys with channel character of multi time slots, as a result difference of different channels is mapped onto transmitting distortion. And mutual information of delivering and receiving terminals＇ channel characters can be told by correctness of the transmission, thus the key distribu- tion and authentication are implemented at the same time. Analysis and simulation reveal that key distribution performance in this method is same as the existing one, and the attack can be recognized in circumstances of channels with strong correlation.