des算法的可视化程序的实现.doc

DES算法的可视化程序的实现

摘  要
本毕业设计研究的是DES算法实现及应用。选择该课题的意义在于：为了防止信息不被非法访问或窃取,实现达到该目的功能软件。DES算法是对称的加密算法，具有速度快，执行效率高等优点，它是由IBM公司研制的一种加密算法.本设计实现了该算法并且集成了保密通信，加密演示，文本文件加密三大功能模块.保密通信模块提供了一个基于C/S结构的保密通信示例。加密演示模块提供了对DES算法的加解密演示功能。文本文件加密模块提供了对文本文件加密并保存密文的功能。整个设计采用JAVA语言实现，DES类提供了两个接口，一个加密接口和一个解密接口，对其进行了封装，以便在其他场合可以提供加解密功能。整个应用程序设计的各个功能模块的执行依靠事件驱动，根据不同的事件原因及事件类型执行不同的功能模块。在保密通信应用中采用了多线程技术，服务器端和客户端集成到同一个面板上，各对端在发送消息时先对消息进行加密，发送线程负责处理加密消息的发送，接收线程负责处理加密消息的解密和显示。本文是针对DES算法实现及其应用所做的工作，主要描述DES算法实现原理和方法，应用场合示例演示，实现方式和方法以及在此过程中运用到的计算机知识。并通过所编写的程序实现了本文的描述。

关键词：DES；保密通信；多线程
 
The Implementation of Visible Software about DES Algorithm
Abstract
The research work of this dissertation is the implementation of software about DES algorithm and its application. The meaning of this dissertation is based on: In order to prevent confidential information being illegally accessed or stolen find some ways to build software which function can reach described before. DES algorithm is one kind of symmetrical encryption algorithm, having highly speed, greatly execution efficiency. It's the result of IBM’s research work. This design implements the algorithm and integrates three modules, which is private communication Encrypting demonstration, text encrypting .The module of private communication provides a sample of C/S based communicate case. The module of encrypting demonstrate displays how to the DES works. The module of text encrypting implements the function of encrypting toward text and can save the cipher to a designated file. This design is coded by JAVA language. I declare a class which named des，and this class has two interfaces for the outside user, one used to encrypt, another decrypt. The two interfaces are encapsulated in the des class, in order to use for other occasions discretely. In this system, I use multi thread technology. The server side and client side are integrated on a panel, when send message, each peer firstly encrypts this message, the sending thread’s responsibility is to send the encrypted message, the receiving thread’s responsibility is to receive message and decrypt the message and then display to the end user! This dissertation implements the described above, briefly discuss the principle of the algorithm, the way and methods of the implementation, much knowledge about computer science. also constructing a software to fulfill described in this dissertation！

Key words: DES; secret communication; multi-thread

目  录
论文总页数：24页
1 引言 1
1.1历史背景 1
1.2国内外现状 1
1.3课题的意义 1
1.4课题的实现方法 1
2 课题描述 2
2.1加密体制与DES算法 2
2.1.1算法与加密体 2
2.1.2加密解密的概念加密方法以及应用 3
2.1.3密码学简介 5
2.1.4算法的安全性 6
2.2算法流程 7
3 算法实现及应用 10
3.1应用程序结构 10
3.2应用程序底层加密接口 11
3.3功能模块定义 13
3.3.1保密通信模块 13
3.3.2加密演示模块 17
3.3.3 文本文件加密模块 20
3.3.4 简单密匙管理模块 20
结    论 22
参考文献 22
致    谢 23
声    明 24