【摘要】 随着无线网络的不断发展,物理层安全问题逐渐成为广泛关注的焦点.针对水声信道存在的多径效应和多普勒效应,如何在合法节点比敌手对声源信息不确定性更高的情况下提取出高度保密的公共密钥这一问题,提出一种基于时变水声信道的物理层密钥生成方案.首次准确刻画出多径多普勒效应下的α阶Rényi熵,并得出合法节点和敌手关于声源序列的不确定性.在此基础上,提出一种具有强安全性的密钥协商协议,该协议利用Hash函数构造一元高阶多项式完成通信双方的身份认证,实现索引序列和预选密钥在公开信道下的安全传输.此外,利用双线性映射设计出一种不依赖随机种子长度与随机性并能抗主动攻击的保密增强协议.通过信息理论,证明了方案的健壮性、保密性和正确性,并得出密钥泄露率和敌手主动攻击成功率的上界.仿真实验表明,当声源信息量为50 000 b时,该方案密钥泄露率的上界为3.74×10^-6,敌手主动攻击成功率的上界为5.468×10^-20,验证了方案的可行性.更多还原

【Abstract】 With the continuous development of wireless networks, the security of physical layer has gradually become the focus of widespread concern. Concerning the problem of how to extract a highly confidential key from the source information when legitimate nodes have more uncertainty than that of eavesdropping node under the circumstances of multipath and Doppler effects in underwater acoustic channel, a time-varying underwater acoustic channel based physical layer secret key generation scheme is proposed. For the first time, the α order Rényi entropy with multipath and Doppler effects is accurately depicted, and the uncertainty of the source sequence from the legitimate nodes and the eavesdropping node is also obtained. On this basis, a key agreement protocol with strong security is proposed, which uses Hash function to construct one-variable high-order polynomial to complete identity authentication for both sides of communication and to realize secure transmission of index sequence and preselected key under the public channel. Moreover, a privacy amplification protocol against active attacks is designed using bilinear mapping, which does not depend on the length and randomness of the random seed. The robustness, confidentiality and correctness of the scheme are proved by the information theory. The simulation results show that the upper bound of key leakage rate is 3.74×10^-6 and the upper bound of active attack success rate is 5.468×10^-20 when the amount of the source information is 50 000 b, which verifies the feasibility of the proposed scheme.更多还原