基于OCDMA与加密算法的跨层安全研究

发布时间：2018-04-04 21:10

本文选题：光码分多址　切入点：加密算法　出处：《深圳大学》2017年硕士论文

【摘要】：光码分多址(Optical Code Division Multiple Access,OCDMA)技术因其具有的接入协议简单、高安全性、软容量等优点,近年来得到了广泛的研究,在军用、电子商务以及民用接入网等场合均有广阔的应用前景。过去,人们普遍认为安全性作为OCDMA系统的固有特征,OCDMA系统理应具备良好的安全性能,但最新研究表明OCDMA系统存在着安全隐患。另外,随着计算机技术的发展,众多本以为安全的加密算法相继被破解,如数据加密标准(Data Encryption Standard,DES)、RSA算法等。事实说明无论OCDMA系统还是加密算法提供单层的安全性都是有限的,各自提高它们安全性同时又受到各种因素制约。但是,如果能结合两者安全性的优点,这些安全问题也许就能迎刃而解了。因此,本文提出基于OCDMA与加密算法的跨层通信系统方案,并首次定量分析了该系统的安全性。本课题来自于国家自然科学基金“自由空间光通信的物理层安全与光编码方法研究”(NSFC61671306)和深圳市学科布局项目“基于光编码物理层安全的光通信关键技术研究”(JCYJ20160328145357990),研究工作主要包括以下几个方面:1)提出基于OCDMA与加密算法的跨层通信系统方案,该系统物理层采用非相干一维时域编码OCDMA系统,而完整的AES加密算法应用于数据层。本文首次提出一种对跨层通信系统安全性进行定量分析的方法,该方法定量分析了窃听信噪比、码字类型、系统用户数、同步/异步、码字拦截时间、密码分析时间等参数对系统安全性能的影响,并采用光系统仿真软件Optisystem结合Matlab搭建了单用户和多用户状态下的系统模型,仿真结果表明了只有在匹配码字解码且正确密钥解密情况下,系统才能恢复出信源信息。2)提出基于WSS的二维可重构OCDMA与加密算法的跨层通信系统方案,该方案使用了一种基于波长选择开关(Wavelength Selection Switch,WSS)的二维可重构的光编/解码器,和采用了超连续谱脉冲光源(使用非线性光纤拓展谱宽),支持了该WSS的动态码重构,提供了最多76个波长选择,并且成功进行了无误码的编/解码传输实验。另外,本文定量分析了该系统的安全性,分析结果说明码字可重构能有效增强系统的安全性,极大提高了窃听者码字拦截难度。最后,根据系统码字可重构以及加密算法可变换,本文研究了跨层通信系统进一步安全性融合、效能提高的可行性,同时分析了系统的安全性。
[Abstract]:Optical Code Division Multiple access OCDMA (OCDMA) technology has been widely studied in recent years because of its advantages of simple access protocol, high security and soft capacity. It has broad application prospects in military, electronic commerce and civil access networks.In the past, it was generally believed that security is an inherent feature of OCDMA systems and that OCDMA systems should have good security performance. However, recent research shows that there are hidden security problems in OCDMA systems.In addition, with the development of computer technology, many encryption algorithms which were supposed to be secure have been cracked one after another, such as data Encryption Encryption standard and RSA algorithm.It is proved that both the OCDMA system and the encryption algorithm provide limited single-layer security, and each of them is restricted by various factors to improve their security.However, if the advantages of both security can be combined, these security problems may be solved.Therefore, a cross-layer communication system based on OCDMA and encryption algorithm is proposed, and the security of the system is quantitatively analyzed for the first time.This topic comes from the National Natural Science Foundation of China "Research on physical layer Security and Optical coding method of Free Space Optical Communication" and Shenzhen subject layout Project "Research on key Technologies of Optical Communication based on Optical coding physical layer Security"JCYJ20160328145357990, the research work mainly includes the following aspects: 1) A cross-layer communication system scheme based on OCDMA and encryption algorithm is proposed.The physical layer of the system uses incoherent one-dimensional time domain coding OCDMA system, while the complete AES encryption algorithm is applied to the data layer.In this paper, a quantitative analysis method for the security of cross-layer communication system is proposed for the first time. The method quantitatively analyzes the signal-to-noise ratio of eavesdropping, codeword type, number of system users, synchronous / asynchronous, codeword interception time, etc.The influence of cryptographic analysis time and other parameters on the security performance of the system is analyzed. The system model under single user and multi-user states is built by using optical system simulation software Optisystem and Matlab.Simulation results show that only when the matching codeword is decoded and the key is decrypted correctly, can the system recover the source information. (2) A cross-layer communication scheme based on WSS is proposed for two-dimensional reconfigurable OCDMA and encryption algorithm.The scheme uses a two-dimensional reconfigurable optical encoder / decoder based on wavelength selection switch wavelength Selection switch (WSS) and a supercontinuum spectral pulse light source (using nonlinear fiber to expand spectrum width to support the dynamic code reconstruction of the WSS.A maximum of 76 wavelength selections are provided, and an error-free coding / decoding transmission experiment is successfully carried out.In addition, the security of the system is quantitatively analyzed in this paper. The results show that codeword reconfiguration can effectively enhance the security of the system and greatly improve the difficulty of intercepting the eavesdropper.Finally, according to the reconfigurable codeword of the system and the transformation of encryption algorithm, this paper studies the feasibility of further security fusion and efficiency improvement of cross-layer communication system, and analyzes the security of the system at the same time.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN918;TN929.1

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