面向物联网多跳中继系统的协作密钥生成方法

摘要

针对物联网多跳中继系统中密钥生成方法速率低的问题,提出一种基于网络编码的协作密钥生成方法.在各节点完成信道估计后,中继节点采用安全网络编码技术辅助通信双方获取相同信道的估计值,同时辅助信息不泄露该信道的任何信息,最后通信双方直接在公共信道上协商得到相同的密钥.理论分析和仿真结果表明,该方法可以有效地提高可达密钥速率,同时增加传输路径,选取跳数少、信道变化大的传输路径,可以进一步提高可达密钥速率.%The achievable key rate of secret key generation method in multi-hop relaying systems was relative low in In-ternet of things. A cooperative secret key generation algorithm based on network coding was proposed to improve the achievable key rate. Firstly, all the nodes send training sequences in turn to estimate the channels. After that the relays employ secure network coding technique to assist the two legitimate users to obtain the correlative observations of the same wireless channel, with nothing leakage about the channel information to the eavesdropper. Finally, the two legiti-mate users agreed on a common secret key directly over the public channel. Theoretical and simulation results validate the performance of the proposed secret key generation algorithm, and obtain that increasing the wireless transmission paths, se-lecting the transmission path with less hops and larger variance channels can further improve the achievable secret key rate.