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网络教育学院本科生毕业论文（设计）题目：数据加密技术的研究综述(模板)学习中心：层次：专科起点本科专业：网络工程年级：2009年秋季学号：20110391CCXX学生：XXXX指导教师：XXX完成日期：2013年03月18日深圳学历教育内容摘要随着计算机网络技术的飞速发展，数据加密技术将成为信息网络安全技术中的核心技术，本文介绍了网络与信息安全技术体系结构，对目前信息加密技术进行了分析，阐述了各类加密算法的优缺点，同时对加密技术的发展趋势进行了描述从最初的保密通信发展到目前的网络信息加密。数据加密技术是指将一个信息经过加密钥匙及加密函数转换,变成无意义的密文,而接收方则将此密文经过解密函数、解密钥匙还原成明文。在竞争激烈的信息时代,客观上需要一种强有力的安全措施来保护机密数据不被窃取或篡改,因此数据加密技术就应运而生。关键词：信息安全；数据加密；加密钥匙；解密钥匙；加密算法深圳学历教育目录内容摘要·····························································································I引言······························································································11概述······························································································21.1背景······················································································21.2本文的主要内容及组织结构························································32数据加密和加密系统·········································································42.1数据加密技术原理····································································42.2数据加密技术的分类及其应用·····················································42.3加密系统体系··········································································52.3.1加密系统的分类······························································52.3.2加密体制存在的问题························································62.4对称加密、非对称加密和数字签名··············································73DES加密标准···················································································93.1DES介绍和DES算法框架···························································93.2DES实例分析···········································································93.3DES的安全性和应用误区·························································123.4DES的拓展············································································123.4.13DES············································································123.4.2AES算法······································································134公开加密算法RSA···········································································144.1RSA的简介············································································144.2RSA算法的结构·····································································144.3RSA算法的案例·····································································144.4RSA探索···············································································225其他加密技术················································································255.1MD5·····················································································255.2可变长密钥块Blowfish加密技术··············································265.3椭圆曲线密码体制··································································27深圳学历教育伪随机数加密技术··································································286结论····························································································32参考文献···························································································33附录一伪随机数加密法的加密和解密程序···············································33深圳学历教育引言随着网络技术的发展，网络安全也就成为当今网络社会的焦点中的焦点，几乎没有人不在谈论网络上的安全问题，病毒、黑客程序、邮件炸弹、远程侦听等这一切都无不让人胆战心惊。病毒、黑客的猖獗使身处今日网络社会的人们感觉到谈网色变，无所适从。用户必需清楚地认识到，这一切一切的安全问题不可一下全部找到解决方案，况且有的是根本无法找到彻底的解决方案，如病毒程序，因为任何反病毒程序都只能在新病毒发现之后才能开发出来，目前还没有哪能一家反病毒软件开发商敢承诺他们的软件能查杀所有已知的和未知的病毒，所以用户不能有等网络安全了再上网的念头，因为或许网络不能有这么一日，就象“矛”与“盾”，网络与病毒、黑客永远是一对共存体。现代的电脑加密技术就是适应了网络安全的需要而应运产生的，它为用户进行一般的电子商务活动提供了安全保障，如在网络中进行文件传输、电子邮件往来和进行合同文本的签署等。其实加密技术也不是什么新生事物，只不过应用在当今电子商务、电脑网络中还是近几年的历史。加密作为保障数据安全的一种方式，它不是现在才有的，它产生的历史相当久远，它是起源于要追溯于公元前2000年（几个世纪了），虽然它不是现在所讲的加密技术（甚至不叫加密），但作为一种加密的概念，确实早在几个世纪前就诞生了。当时埃及人是最先使用特别的象形文字作为信息编码的，随着时间推移，巴比伦、美索不达米亚和希腊文明都开始使用一些方法来保护他们的书面信息。近期加密技术主要应用于军事领域，如美国独立战争、美国内战和两次世界大战。最广为人知的编码机器是GermanEnigma机，在第二次世界大战中德国人利用它创建了加密信息。此后，由于AlanTuring和Ultra计划以及其他人的努力，终于对德国人的密码进行了破解。当初，计算机的研究就是为了破解德国人的密码，人们并没有想到计算机给今天带来的信息革命。随着计算机的发展，运算能力的增强，过去的密码都变得十分简单了，于是人们又不断地研究出了新的数据加密方式，如利用ROSA算法产生的私钥和公钥就是在这个基础上产生的。本文主介绍究各种加密算法以及各类加密算法的优缺点，以及各类加密技术在军事、科学等多方面的应用。深圳学历教育背景当今网络社会选择加密已是我们必然选择，一方面是因为在互联网上进行文件传输、电子邮件商务往来存在许多不安全因素，特别是对于一些大公司和一些机密文件在网络上传输。而且这种不安全性是互联网存在基础——TCP/IP协议所固有的，包括一些基于TCP/IP的服务；另一方面，互联网给众多的商家带来了无限的商机，互联网把全世界连在了一起，走向互联网就意味着走向了世界，这对于无数商家无疑是梦寐以求的好事，特别是对于中小企业。为了解决这一对矛盾，选择数据加密以及基于加密技术的数字签名已成为必然选择。随着信息技术的发展与应用，信息安全的内涵在不断的延伸，从最初的信息保密性发展到信息的完整性、可用性、可控性和不可否认性，进而又发展为攻（攻击）、防（防范）、测（检测）、控（控制）、管（管理）、评（评估）等多方面的基础理论和实施技术。就理论研究而言，一些关键的基础理论需要保密，因为从基础理论研究到实际应用的距离很短。现代信息系统中的信息安全其核心问题是密码理论及其应用，其基础是可信信息系统的构作与评估。总的来说，目前在信息安全领域人们所关注的焦点主要有以下几方面：1）密码理论与技术；2）安全协议理论与技术；3）安全体系结构理论与技术；4）信息对抗理论与技术；5）网络安全与安全产品。自从1976年公钥密码的思想提出以来，国际上已经提出了许多种公钥密码体制，但比较流行的主要有两类：一类是基于大整数因子分解问题的，其中最典型的代表是RSA；另一类是基于离散对数问题的，比如ElGamal公钥密码和影响比较大的椭圆曲线公钥密码。由于分解大整数的能力日益增强，所以对RSA的安全带来了一定的威胁。目前768比特模长的RSA已不安全。一般建议使用1024比特模长，预计要保证20年的安全就要选择1280比特的模长，增大模长带来了实现上的难度。而基于离散对数问题的公钥密码在目前技术下512比特模长就能够保证其安全性。特别是椭圆曲线上的离散对数的计算要比有限域