基于信道特征提取的密钥生成研究

发布时间：2019-04-15 22:32

【摘要】：最近几年,无线通讯技术获得了迅猛的发展,无线信道的开放性使得这种通信方式面临着与有线通信方式相比更为严峻的安全威胁。传统安全方案的安全性一方面基于算法的复杂性,另一方面依靠密钥的随机性和保密性。要增强安全方案的安全性,传统手段是设计更为复杂的安全算法或增加密钥的分组长度,但这样就不断的增加了算法执行的复杂度,不利于无线通讯设备朝小型化发展的趋势。物理层安全技术突破了传统安全解决方案,它利用物理信道具有随机性这一天然优势来产生密钥,这既能大大提高密钥的生成效率,在理想情况下,还能够逼近香农提出的“一次一密”保密方案,从而有效提高安全方案的安全性能。所以物理层安全技术自提出之日起,就引起了国内外学者的广泛关注。在物理层安全技术中,基于信道特征的密钥产生技术是其中最为关键的技术。本文正是针对这一技术展开研究,主要研究内容如下:(1)对于现有的基于物理信道的密钥生成方案进行了详细的分析和总结。本文发现现有方案存在以下三个主要缺陷:第一,在主动攻击者实施干扰信道攻击时,没有较优的密钥生成方案来抵御这类攻击;第二,缺乏针对超宽带系统的最佳特征提取算法;第三,在密钥协商阶段,现有大部分方案仅仅只考虑了密钥一致性问题,而忽略了密钥协商过程中的初始密钥泄漏问题。(2)针对第一个缺陷,本文研究了基于随机探测信号的密钥生成方案。该方案将现有生成方案中的固定探测信号改为随机探测信号,再与信道冲激函数进行卷积,从而得到新的特征提取信号。这种方案所生成的密钥不仅包含信道的随机性,而且还包含随机信号的随机性,因此,它能够较好地抵御信道主动干扰攻击。(3)针对第二个缺陷,本文提出了基于多径时延优选提取算法的密钥生成方案。该算法的原理是对接收端所接收到的多径时延按照互相度的大小进行快速排序,选出相关性最大的k个值作为信道特征进行提取。基于这种算法的密钥生成方案能够比较大地提高初始安全密钥的一致性,从而大大降低密钥协商的开销。(4)针对第三个缺陷,本文研究了基于混淆及RS码协商的密钥生成方案。该方案的原理是在协商阶段先对需要传输的密钥进行混淆处理,再利用RS码对两端初始密钥进行纠错得到完全一致的密钥。这种方案既保证了两端密钥的一致性,同时也降低了密钥在传输过程中的泄漏风险。(5)本文研究了将以上三种改进算法结合到一起的方案,给出了仿真分析。
[Abstract]:In recent years, the wireless communication technology has been developed rapidly. The openness of the wireless channel makes this communication mode face more serious security threat than the wired communication mode. The security of traditional security scheme is based on the complexity of the algorithm on the one hand, on the other hand, depends on the randomness and confidentiality of the key. In order to enhance the security of the security scheme, the traditional method is to design more complex security algorithms or increase the packet length of the key. However, it increases the complexity of the algorithm execution and is not conducive to the development of wireless communication equipment towards miniaturization. The physical layer security technology breaks through the traditional security solution. It makes use of the natural advantage of the randomness of the physical channel to generate the key, which can not only greatly improve the efficiency of generating the key, but also under the ideal circumstances, It can also approach Shannon's one-time-one-secret security scheme, so as to effectively improve the security performance of the security scheme. Therefore, the physical layer security technology has attracted the attention of scholars both at home and abroad since it was put forward. Among the physical layer security techniques, key generation based on channel characteristics is the most important one. The main contents of this paper are as follows: (1) the existing key generation schemes based on physical channel are analyzed and summarized in detail. In this paper, we find that there are three main defects in the existing schemes: first, when active attackers carry out interference channel attacks, there is no better key generation scheme to resist such attacks; Secondly, there is a lack of optimal feature extraction algorithm for UWB systems. Thirdly, in the phase of key agreement, most of the existing schemes only consider the problem of key consistency, but ignore the initial key leakage problem in the process of key agreement. (2) for the first defect, In this paper, a key generation scheme based on random detection signal is studied. In this scheme, the fixed detection signal in the existing generation scheme is changed into a random detection signal, and then convolution with the channel impulse function to obtain a new feature extraction signal. The key generated by this scheme not only contains the randomness of the channel, but also the randomness of the random signal, so it can resist the channel active interference attack well. (3) in view of the second defect, In this paper, a key generation scheme based on multi-path delay optimization extraction algorithm is proposed. The principle of this algorithm is that the multipath delay received by the receiver is sorted quickly according to the degree of mutual phase, and the k values with the greatest correlation are selected to extract the channel features. The key generation scheme based on this algorithm can greatly improve the consistency of initial security keys, thus greatly reducing the overhead of key agreement. (4) aiming at the third defect, In this paper, a key generation scheme based on confusion and RS code agreement is studied. The principle of this scheme is to obfuscate the key that needs to be transmitted in the negotiation phase, and then use RS code to correct the initial keys at both ends to get a completely consistent key. This scheme not only guarantees the consistency of the keys at both ends, but also reduces the leakage risk of the keys in the process of transmission. (5) in this paper, the scheme combining the above three improved algorithms is studied, and the simulation analysis is given.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN918.4

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