目 录
第一章 概述 ........................................................................................... 2
1.1课题背景 ............................................................................................................................ 1
1.2数字签名及其应用 ............................................................................................................ 1
1.2.1数字签名概述 .......................................................................................................... 1 1.2.2数字签名的应用 ...................................................................................................... 2 1.3 课题内容 ........................................................................................................................... 3
第二章 数字签名软件的技术支撑 .............................................................. 4
2.1 RSA加密算法 ................................................................................................................... 4
2.1.1 公钥和私钥的产生 ................................................................................................. 4 2.1.2 加密消息 ................................................................................................................. 5 2.1.3 解密消息 ................................................................................................................. 5 2.1.4 安全 ......................................................................................................................... 5 2.1.5 实现细节 ................................................................................................................. 6 2.2 数字签名原理 ................................................................................................................... 7 2.3 散列函数 ........................................................................................................................... 7
2.3.1散列函数的性质 ...................................................................................................... 8 2.3.2 散列函数的应用 ..................................................................................................... 8 2.3.3 MD5算法 .............................................................................................................. 10 2.3.4 SHA-1算法 ............................................................................................................ 11 2.4 C#和.NET ........................................................................................................................ 11
第三章 系统的分析与设计 ................................................................... 13
3.1需求分析 .......................................................................................................................... 13
3.2 总体设计 ......................................................................................................................... 13 3.3 功能模块的划分 ............................................................................................................. 15 3.4 各功能模块的介绍 ......................................................................................................... 16
第四章 系统的实现 .................................................................................. 18
4.1 RSA加密算法的实现 ..................................................................................................... 18
4.1.1 公私密钥的生成 ................................................................................................... 19 4.1.2 使用私钥加密 ....................................................................................................... 20 4.1.3 使用公钥解密 ....................................................................................................... 21 4.1.4 其他 ....................................................................................................................... 21 4.2 散列函数 ......................................................................................................................... 21 4.3 数字签名的实现 ............................................................................................................. 22
4.3.1 设计思想 ............................................................................................................... 22
4.3.2 系统实现 ............................................................................................................... 24 4.4 本章小结 ......................................................................................................................... 33
结束语 ....................................................................................................... 34
致 谢 ....................................................................................................... 35
摘 要
随着Internet的发展，电子商务已经逐渐成为人们进行商务活动的新模式，越来越多的人通过Internet进行商务活动。电子商务的发展前景十分诱人，而其安全问题也变得越来越突出，如何建立一个安全、便捷的电子商务应用环境，对信息提供足够的保护，已经成为商家和用户都十分关心的话题。
系统综合运用了RSA算法原理，散列函数以及C#和.NET编程技术，实现了基于RSA算法的数字签名系统。经过测试表明，系统运行可靠稳定，实现了保证信息完整性、鉴别发送者的身份真实性与不可否认性目标。
本文基于数字签名技术在电子商务中的应用，对公钥密码体制中的广泛流行的RSA算法做了深入的研究并主要阐述了利用C#语言实现基于RSA算法的数字签名方法。从两大基本模块——签名系统和认证系统着手，对数字签名进行了详细的说明和分析。 关键词：数字签名；公钥密码体制；RSA；电子商务；加解密
ABSTRACT
With the development of Internet，E-commerce has gradually become a new model of business activities，more and more people take up business affairs through the Internet. Prospects for the development of e-commerce is very tempting，and the security issues are becoming increasingly prominent.
Many technologies have been adopted in the system, such as algorithm RSA, hash function, C# and .NET programming technology. And the Digital Signature system is based on algorithm RSA. The tests of application show that this system is reliable and achieves the design object of the integrity of information, identification of the sender's identity and the authenticity of the undeniable..
Based on digital signature technology in the application of e-commerce，we conduct a study about the algorithm RSA which is very popular in the public-key cryptosystem，and we mainly explain the implementation of the Digital Signature based on algorithm RSA in C#. From the two basic systems -- the signature system and the authentication system, we did the detailed description and analysis of digital signature.
Key words: digital signature; public-key cryptosystem; RSA; Eletronic Commerce; encryption and decryption