【作者】 郑骁鹏；

【导师】 田小建；

【作者基本信息】 吉林大学 ， 电路与系统， 2009， 博士

【摘要】 随着现代电子信息技术及互联网技术的飞速发展,基于Internet和局域网的各种应用项目越来越深入到国家和人民的工作与生活之中,信息交换及数据存储也成为了信息网络中最重要的组成部分。如何保证信息安全已成为业界关注的焦点,对加密技术的研究也变得越来越重要。传统的加密方式已经逐步被不断发展的密码分析技术成功破解或加/解密速度已经缓慢得无法适用于高速发展的网络传输速度。混沌系统以其对系统初值及参数的高度敏感性、遍历性、轨道不可预知性等优良的伪随机特性,已经成为一种引起国内外学者浓厚兴趣和广泛研究的应用于信息加密的前沿课题。本文首先介绍了信息安全和现代密码学的主要技术和方法,由此提出了对当前加密技术的新要求,通过对混沌理论及光学混沌的简要介绍,说明了混沌理论及技术在信息加密领域的优势和研究前景。然后在分析环形掺铒光纤激光器系统的动力学特性基础上,利用带光延迟反馈回路的单环掺铒光纤激光器(ODF-EDFL)系统作为混沌序列发生器来生成两个实值混沌序列,引入变化率的概念将其分别转化为二值混沌序列,再通过添加m序列扰动的方式对二值混沌序列进行混合优化,并通过统计特性分析和序列检验证明了此混合二值混沌序列优良的随机特性和应用于加密算法设计的可行性。接下来以此混合二值混沌序列为基础加密序列,通过对当前数字图像加密技术和数字水印技术的分析研究,设计了一系列新的数字图像加密算法和彩色图像水印算法,并通过仿真实验和安全性分析及抗攻击能力测试验证了算法的有效性和安全性。最后结合当前的数据库加密技术探讨了混沌加密思想在海关数据库加密中的应用前景,设计了利用ODF-EDFL混沌系统来改进分组加密算法中的AES加密算法和公开密钥中的RSA算法的方法,并通过仿真实验证明了此方法的有效性。本文的研究将掺铒光纤激光器混沌系统引入混沌加密领域,提出并验证了一些新的加密算法,为光学混沌加密的进一步研究做出了一定的理论拓展和应用探索。更多还原

【Abstract】 With the fast development of modern information technology and the integration of global information network, information system has become a pivotal infrastructure that is depended by politics, economy, education and individual life etc. As the information network bring great convenience to the whole world, the information system security has become the focus of the whole society, the information security has become a very important matter which relates to the national political stability and social harmony and the orderly development of economy. In recent years, some more advanced and more promising theories and methods are introduced the field of information security. The chaos theory possesses several specific characteristics such as good pseudo random properties, rail unpredictability, the extreme sensitivity to initial conditions and the control parameters, some properties match to cryptography. Therefore the chaos theory which locates the across of the two fields of international nonlinear science and information science has become a hot research topic of secure communication and information encryption technology.Since the British mathematician Matthews put forward the thought based on chaotic encryption in 1989, chaotic cryptography has experienced the development process for 20 years. During this period, new chaos systems and new encryption schemes applied to data encryption, image watermark encryption, video encryption, encryption and other fields incessantly. The generation and application of chaos phenomena in optical systems has become an important part of the research on chaos system in resent years, However most of the study focused on the field of chaos synchronization secret communication. The study of this dissertation introduces the optical chaos system to the chaotic encryption field for the first time. The dissertation studies the applications of digital image encryption algorithm and digital watermark algorithm by utilizing the chaotic sequences that generated by the erbium-doped fiber laser chaotic system. Meanwhile, it also analyzes and discusses the application of chaos theory in the database encryption application. In this dissertation I proposed and studied the feasibility of improving the database core encryption algorithm by using the chaotic sequences which generated by the erbium-doped fiber laser. The whole dissertation can be divided into five parts:The first part is the literature review of the whole dissertation. First, based on new requirements of the encryption technology of the information security to modern cryptography, via the brief introduction of the chaos theory and optical chaos, this part puts forward the background and significance of the subject research. Then I introduce the development process of chaos from its birth to being admitted, and it plays more and more important role in various fields. The first part introduces two kinds of define methods of chaos in mathematics: the definitions of Li-York’s and Devaney’s, and summarizes the basic characteristics of chaotic systems according to the analysis of the chaotic concepts. Describes the analysis method of chaotic systems such as bifurcation diagram, attributor, Lyapunov exponent, the power spectral density and Kolmogorov entropy, etc. Finally, based on the introduction of information security and encryption algorithm of cryptography, I analyzed the similarities between chaos and cryptography, summarized the recent research progress and the main application methods that introduce chaotic system into the field of information security. Thus make the preparation for the research in next phase.The second part of the dissertation mainly studies on erbium-doped fiber laser chaotic sequence. Based on the introduction of the study on optical chaos, I setouts the system framework and luminescence principle of erbium-doped fiber laser, and discusses the chaotic theory and methods of erbium-doped fiber laser by analyzing the dynamic behavior and normalized equation. Then based on the study, the method that generates chaos by adding optical delay feedback to the single ring erbium-doped fiber lasers is discussed in detail, and the complicated nonlinear dynamic behavior and rich chaos characteristics of this system are proved by using the bifurcation diagram and Lyapunov exponent method. Finally, the assume that using erbium-doped fiber ring lasers with an optical delay feedback (ODF-EDFL) chaotic systems as chaos sequence generator is proposed. I put forward the concept of change rate of ODF-EDFL chaotic system to translate the real value chaotic sequences into binary chaotic sequences, and I also design a new optimization model that disturbs the mixed binary chaotic sequences by m-sequence: firstly the two binary chaotic sequences that are generated by ODF-EDFL chaotic system are mixed by XOR operator, then disturbed the mixed sequence by using m-sequence which has good random characteristics. This model improves the uniform distribution characteristic of the ODF-EDFL chaotic sequences greatly. These statistical tests (such as balance test, runs test, serial test, auto-correlation test) verified the excellent random statistical characteristics of the mixed chaotic binary sequence. This mixed binary chaotic sequence set up better foundation for the design of the following encryption algorithm based on chaotic sequence.The third part of the dissertation mainly studies on the encryption algorithms which utilizes single ring erbium-doped fiber laser mixed binary chaotic sequence to design digital image. This part first introduces the basic principles and methods of image encryption, analyzes the recent research status and achievements of digital image encryption, and the principle of space scrambling of Arnold transformation and magic cube transform are discussed concretely. Then a new image encryption scheme is proposed via analyzing those encryption algorithms: Generates the value chaotic pseudo-random sequences and the mixed binary chaotic sequence by applying ODF-EDFL chaotic system, meanwhile, changes the pixel grey value of the image by using the binary sequence and to confuse the pixel position by the two real-value chaotic sequences by using a novel method of space scrambling to digital images named pixels-minesweeper-scrambling (PMS). Finally the excellent encryption and decryption of this algorithm is proved by the results of simulation and security analyzing. This encryption algorithm has very strong sensitivity and better statistical characteristics. It even has more outstanding performance in the condition of the anti-interference and resists malicious attacks.The fourth part of the dissertation mainly studies on the design of color image watermarking algorithms based on single ring erbium-doped fiber laser mixed binary chaotic sequence. Firstly this paper introduces the study background and significance of digital watermarking, expounds the basic principle, characteristic and classification of digital watermarking technology. Then the conception and classification of wavelet transform are discussed, this part emphatically analyzed the definition of discrete wavelet transform (DWT) and analyzed the advantage of using Mallat algorithm technique to decompose the digital images in the field of design digital image watermarking algorithm. Finally, the erbium-doped fiber laser chaotic system is applied to image watermarking research field for the first time, which based on the analysis of chaotic systems in application of digital watermarking. Design and implement a novel color image watermarking algorithm that using ODF-EDFL chaotic sequences to encrypt watermark information, this novel algorithm can also embed and extract watermark by using the characteristics of human visual sense complements and DWT technology. It can improve the effect of watermark image encryption results and ability to resistance crack after applying the optimized ODF-EDFL mixed binary chaotic sequences to encrypt watermarks; The design of embedding watermark information into the green components in color image improved the ability of this algorithm on resistance against JPEG lossy compression. And the embedding algorithm based on DWT enhances the robustness of against other attacks. The computer simulation experiment and attack ability test proved the outstanding visual effect and the ability to resist attacks of this algorithm.The fifth part of the dissertation mainly discusses the application of chaos theory and technology in customs database encryption. First the necessity and meaning of encrypting the customs database which deposit important sensitive data on the current situation of information security are discussed in this paper. Then the main technology of database encryption has been divided and reviewed based on the analysis of database security requirements and target. Finally, according to the front part study in the chaotic encryption technology field, the conception and discussion on the application of the customs database encryption system by using chaotic technique is put forward. Furthermore, the encryption algorithm such as AES, RSA etc which play a key role in database encryption are improved by using ODF-EDFL mixed chaotic sequences, and the simulation results show the feasibility and availability of improve the ability to crack which can expand key space of encryption algorithm.The research and numerical simulation experiment of chaos encryption technology that based on erbium-doped fiber laser system in this dissertation introduce erbium-doped fiber laser chaotic system into chaos encryption fields, and provide some theoretical and experimental basis for the application in optical chaotic encryption and confidential communications field, and even made some exploration and achievement.更多还原