基于計算機并口的智能軟件加密狗設(shè)計

電子信息工程論文編號:DZXX046  論文字?jǐn)?shù):16511,頁數(shù):55

目錄
摘要 I
ABSTRACT II
第1章 緒論 1
1.1 背景 1
1.2 研究內(nèi)容 2
第2章 設(shè)計方案論證 4
2.1 單片機的選擇 4
2.2 微機接口的選擇 5
第3章 系統(tǒng)硬件設(shè)計 6
3.1 單片機簡介 6
3.2 打印機端口簡介 8
3.3 單片機與打印機端口電路設(shè)計 12
3.4 用Protel DXP工具制作原理圖和PCB板 13
第4章 系統(tǒng)軟件設(shè)計 20
4.1 加密算法分析 20
4.1.1 密碼學(xué)的基本概念 20
4.1.2 三種加密算法的比較 23
4.2 用MPLAB工具調(diào)試編程 26
4.3 使用程序外殼工具 29
第5章 畢業(yè)設(shè)計總結(jié) 31
致謝 32
參考文獻 33
附錄 單片機程序 34

摘要

 近些年來，人們開始越來越重視對軟件的保護。軟件開發(fā)者除了采用法律手段保護自己的利益外，還應(yīng)著重從技術(shù)上采取手段保護自己的知識產(chǎn)權(quán)，其方法就是采用軟件加密技術(shù)。微機軟件開發(fā)商為了保護自己的研究成果， 往往都希望對軟件系統(tǒng)進行加密。早期采用的加密方式（如硬盤加密、加密卡等）都因為有這樣那樣的缺點而被淘汰，取而代之的加密狗加密技術(shù)是近幾年來興起的一種較為理想的加密手段。
 加密狗的設(shè)計沒有千篇一律的模式可循，往往是仁者見仁，智者見智，也正因為如此，加密狗才有對系統(tǒng)加密存在的價值。本文介紹一種高級加密狗技術(shù)，它利用插接在微機并行打印口上的加密裝置與專用加密程序互相配合來實現(xiàn)對密碼的寫入、保存、讀取和校對。它將密碼分成接收碼和返回碼兩部分，接收碼由PC機加密軟件提供，返回碼由接收碼和單片機內(nèi)部軟件算法產(chǎn)生，這種加密方式具有保密性更強，破密難度更大，且可應(yīng)用于不同軟件系統(tǒng)等特點。

關(guān)鍵詞：軟件狗，PIC單片機，加密，并口，解密

ABSTRACT

 In recent years, people have begun paying more and more attention to the protection of the software. Besides legal means, software developer should stress on technical means to protect their own property rights and interests. Software encryption techniques is the way. To protect their own development and research results, computer software developers often want to do software encryption. Early use of encryption methods (such as hard disk encryption, encryption card, etc.) are eliminated, because of all kinds of defects. Instead, encryption technique of softdog is an arising ideal means of encryption in recent years.
 The design and implementation of software has no stereotyped pattern, people can develop and do at their own wise way. And this presents the value of softdog encrypting system. This thesis introduces one kind of super softdog technique. It utilizes the plug-in encryption facility of PC LPT and private encryption procedures to achieve the passwords input, preservation, reading and proof. It has 2 parts of passwords, input codes and return codes. Input codes is from encryption software of PC, and return codes is from input codes & the internal software of SCM. This encryption method is a more confidential, of much more password broken difficulty and can be applied to many different software systems, and other excellent features.
 Keywords: Softdog , PIC MCU, Encryption, Parallel port, Decryption