准静态环境下的回溯加扰密钥生成算法  

Backtracking scrambled key generation in quasi-static environment

作　　者：王丹[1] 方磊[1] 何斌 陈发堂[1] WANG Dan;FANG Lei;HE Bin;CHEN Fatang(School of Communications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《南京信息工程大学学报》2024年第5期688-696,共9页Journal of Nanjing University of Information Science & Technology

基　　金：重庆市自然科学基金(cstc2021jcyj-msxmX0454)。

摘　　要：物理层安全技术利用无线信道环境动态生成密钥,但在准静态环境中,信道变换缓慢导致密钥的随机性及安全性不足,因而提出一种回溯加扰密钥生成算法(Backtracking Scrambled Key Generation,BSKG).首先,拆分信道系数的实部虚部量化以生成更长的密钥.调和后,再利用本次密钥与上一次密钥间的不一致索引总和生成扰码并与本次密钥加扰.仿真结果表明,较现有的多维信息、添加人工随机性的密钥生成方法,本文算法具有更高的密钥生成速率和安全性,且随“一次一密”密钥生成次数的增加,即使被窃听到较相关的信道系数,密钥泄露率仍接近0.5.利用语义安全和信息论不等式分别估计一般及恶劣信道条件成功窃听的概率上界及其随密钥生成次数N的变化情况,给定某些参数,得到这两种情况下的概率上界分别为2-77N和2-23N.Physical layer security techniques utilize the wireless channel environment to dynamically generate keys,however,in quasi-static environment,slow channel transformation leads to insufficient key randomness and se-curity.Here,a Backtracking Scrambled Key Generation(BSKG)algorithm is proposed.First,the real and imaginary parts of the channel coefficients are split and quantized to generate a longer key,which is reconciled,then the sum of the inconsistent indexes between the current key and previous key is used to generate a scrambling code to scram-ble the current key.Simulation shows that,compared with the existing multi-dimensional information and artificial randomness key generation method,the proposed algorithm has higher key generation rate and security,and the key leakage rate is close to 0.5 with the increase of the one-time pad key generation times,even if more relevant chan-nel coefficients have been eavesdropped.The upper bounds on the probability of successful eavesdropping and their variations with the number of key generation N for general and bad channel conditions are estimated using semantic security and information-theoretic inequalities,respectively,when giving certain parameters,the upper bounds for these two cases turn out to be 2-77N and 2-23N.

关 键 词：物理层安全 一次一密 准静态环境 回溯加扰 

分 类 号：TN918.82[电子电信—通信与信息系统]