Secret Key Generation for Two-way Amplify-and-forward Relay Channel
Wei Hao① Zheng Bao-yu① Hou Xiao-yun①② Ji Xiao-dong①
①(Institute of Signal Processing and Transmission, Nanjing University of Posts and Telecommunications, Nanjing 210003, China) ②(National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China)
Abstract：According to the characteristics of two-way amplify-and-forward relay channel, this paper extracts secret key by exploiting the reciprocity of wireless multipath channel in time division system and the commutative law of convolution operation. So, the secret key can be generated with the channel estimation to overcome the drawback of the key pre-distribution mechanism. The recovery algorithm based on compressive sensing theory is used for channel estimation because of the sparsity of the wireless multipath channel. This paper proposed two new schemes based on the relative-amplitude and the relative-phase for secret key generation and compared them to the scheme based on the relative-delay. Simulation results show that all three schemes can achieve high key generation consistency probability, and present eavesdropping by the third party to ensure the security of the physical layer communication.
2013, Vol. 35 
