溷沌理论在密码学中的应用.docVIP

-  PAGE 10 - -  PAGE 36 混沌理论在密码学中的应用 摘要：在信息化社会中，信息已经成为决定社会与人行为的主导力量，信息必威体育官网网址问题日趋受到重视。加密是解决信息安全的关键技术，信息的必威体育官网网址性、完整性和可用性，都需要采用加密技术来实现。现代高性能的计算机能够自动分析和截获程序，每秒可以有哪些信誉好的足球投注网站数百万个底码，从而对传统加密算法的安全性构成严重的威胁。 混沌是确定性系统中的一种貌似随机的运动。混沌信号具有遍历性、宽带性、对初始条件的敏感性、快速衰减的自相关和微弱的互相关性等特点，这些性质与密码学中Shannon经典模型中所要求的混淆和扩散性质类似，因而混沌在必威体育官网网址通信领域有着极大的应用前景，引起了密码学界的广泛关注。 本文就是从实际需要和理论研究出发，先对混沌的基本概念及特性给予了详细介绍，并指出了混沌研究的意义。并基于混沌序列的许多优良特性，结合混沌理论在密码学中的应用，提出了混沌序列加密算法。 本文选Logistic映射为研究对象，给出了混沌加密的实现机制，并详细论述了加密算法的实现过程；由于简单混沌加密还存在着许多问题，本文还提出了加密算法的改进方法，并对改进后的加密算法的安全性能给予了详细分析。 关键词　混沌时间序列；Logistic映射；密钥；加密 Producing Encryption Software System Basing on Chaotic Time Series Abstract:In the information society, the information has become the dominant force determines mans behaviors and the resolution of community. With the development of IT, the information’s security has become more and more important. The encryption technique is the key to guarantee information’s security. The encryption technique can guarantee information’s confidentiality, completeness and the usability. The contemporary high quality computer can automatically analysis and intercept the program, and can decrypt a few million yards per second, which gravely intimidates the secure quality of the tradition encryption algorithm. Chaos is one kind of motion, which is looked like a random one in the certain system. The chaotic signal bears some features such as the ergodicity, broadband, the sensitivity to initial condition, autocorrelation, feeble cross-correlation and so on, these features resemble in the confusion and the diffusion which are demanded in Shannons classics patterns in the cryptography. As a result, there is extremely great application foreground in the secure communications for chaos, which arouses the wide-ranging concern of cryptography circles. The aim of this paper is practice needs and theory researches. First ,we offer detailed introducing to the basic concept and the property of chaos，and point out the chaos research sense. Then we propose the ch