基于水声信道的隐蔽密钥协商方案  

Covert secret-key agreement scheme based on an underwater acoustic channel

作　　者：徐明[1,2] 冯赫鑫 关佶红[2,3] Ming XU;Hexin FENG;Jihong GUAN(College of Information Engineering,Shanghai Maritime University,Shanghai 201306,China;College of Electronics and Information Engineering,Tongji University,Shanghai 201804,China;Key Laboratory of Embedded System and Service Computing(Tongji University),Ministry of Education,Shanghai 201804,China)

机构地区：[1]上海海事大学信息工程学院,上海201306 [2]同济大学电子与信息工程学院,上海201804 [3]嵌入式系统与服务计算教育部重点实验室(同济大学),上海201804

出　　处：《中国科学：信息科学》2023年第6期1096-1110,共15页Scientia Sinica(Informationis)

基　　金：国家自然科学基金联合重点项目(批准号:U1936205);国家自然科学基金面上项目(批准号:62172269);中国博士后科学基金项目(批准号:2014M561512)资助。

摘　　要：水声信道环境下,传统的密钥协商协议更容易遭受信息泄漏等安全威胁,而现有的隐蔽密钥协商协议由于受限于平方根定律,隐蔽通信速率不超过O(1/√n).为解决上述难题,本文提出了一种基于水声信道的隐蔽密钥协商方案.在优先提取阶段,发送方以一定的功率向接收方发送均匀分布的随机消息,而接收方根据水下噪声方差信息,通过Gibbs采样计算出估计消息,并使用对数似然比检验获取初始密钥来减少消息传输时的不确定性和误比特率.信息调和阶段,发送方将伴随式发送给接收方,而接收方将接收到的伴随式与优先提取阶段得到的对数似然比序列进行联合解码来获得错误比特的位置信息,经过比特翻转后得到与发送方完全一致的最终密钥.通过假设检验理论和信息论,证明了方案的保密性、隐蔽性和可靠性.仿真结果表明,所提方案比现有方案性能有所提升.In an underwater acoustic channel (UAC) environment,traditional secret-key agreement protocols are more vulnerable to security threats,such as information leakage.Moreover,the covert communication rate of existing covert secret-key agreement protocols does not exceed O(1/√n) due to the square root law.To solve the above problems,this paper proposes a covert secret-key agreement scheme based on a UAC.In the advantage distillation stage,the transmitter sends uniformly distributed random messages to the receiver within a certain range of power.The receiver calculates the estimated messages using Gibbs sampling according to the variance of the underwater noise.The receiver also uses the log-likelihood ratio (LLR) test to extract the initial key so as to reduce the uncertainty and the bit error rate of the data transmission between two legitimate parties.In the information reconciliation stage,the receiver jointly decodes the received syndrome and the LLR sequence obtained during the advantage extraction stage to obtain the location information of the error bits andfinally obtains a key that is identical to the one in the transmitter after bit-flipping.The secrecy,covertness,and reliability of the proposed scheme are proved by the theory of hypothesis testing and information theory.The simulation results show that the proposed scheme improves performance compared with the existing scheme.

关 键 词：水声信道 隐蔽密钥协商 优先提取 信息调和 对数似然比检验 

分 类 号：TN929.3[电子电信—通信与信息系统]