静态场景下基于RIS天线的物理层密钥生成方案  

Secret key generation scheme based on RIS antenna for static environments

作　　者：杨杰 季新生[1,2] 黄开枝 赵见磊[2] 管新荣 Jie YANG;Xinsheng JI;Kaizhi HUANG;Jianlei ZHAO;Xinrong GUAN(National Digital Switching System Engineering&Technological R&D Center,Zhengzhou 450002,China;Purple Mountain Laboratories:Networking,Communications and Security,Nanjing 211189,China;College of Communication Engineering,Army Engineering University of PLA,Nanjing 210007,China)

机构地区：[1]国家数字交换系统工程技术研究中心,郑州450002 [2]网络通信与安全紫金山实验室,南京211189 [3]陆军工程大学通信工程学院,南京210007

出　　处：《中国科学：信息科学》2022年第2期253-269,共17页Scientia Sinica(Informationis)

基　　金：国家重点研发计划课题(批准号:2020YFB1806607);国家自然科学基金(批准号:61871404,62171461);重点院校和重点学科专业建设项目资助。

摘　　要：针对静态环境下密钥容量低的问题,首次将RIS天线配置在基站设备端用于密钥生成,通过捷变控制RIS单元相移变化,生成随机快变波束,并与原通信信道合并构成新的等价通信信道,从而使密钥容量不受制于自然信道变化速度.然后推导了该方案下密钥容量闭式解,理论分析及仿真表明使用有限单元即可达到与快变信道环境下同等性能,相较于RIS作为反射面部署的方案,在密钥容量增益和防信息泄露等方面具有明显优势.为进一步发挥RIS增益,提出将部分单元用于密钥生成,部分单元用于波束赋形的联合设计方案,推导了该方案下闭式解.最后,在满足密钥容量和通信性能的基础上,给出了最优资源分配策略,仿真表明可以实现密钥容量与通信性能联合提升.A conventional secret key generation scheme achieves a low secret key rate in static environments.To solve this problem,the reconfigurable intelligent surface(RIS)antenna is merged with the device at the base station and is firstly proposed for secret key generation.By tuning the phase shifts at the RIS,a random varying beam can be generated and combined with the original wireless channel to form a new equivalent channel so that the key capacity is not subject to the time variance of the wireless channel.Then the closed-form solution is derived.Theoretical analysis and simulation show that the performance can be increased to that of a fast varying channel with limited radiating units.Moreover,the proposed scheme is superior to the existing schemes,in which the RIS is used as a reflective surface,over performance gain and preventing information disclosure.To further develop the gain of RIS,a joint design scheme is proposed,where some units are used for key generation,and some units are used for beamforming.Finally,the joint’s closed-form solution scheme is derived.Finally,on the basis of satisfying the key capacity and communication performance,an optimal resource allocation strategy is proposed.Simulation results illustrate that the key capacity and communication performance can be improved simultaneously.

关 键 词：智能超表面 密钥生成 物理层安全 静态场景 资源分配 

分 类 号：TN918.4[电子电信—通信与信息系统]