圖片文件中的信息隱藏和還原的設(shè)計

論文字?jǐn)?shù):9661,頁數(shù):24

摘    要
隨著信息技術(shù)、網(wǎng)絡(luò)技術(shù)、電子商務(wù)的迅速發(fā)展,網(wǎng)絡(luò)信息安全將全方位地危及社會的經(jīng)濟、政治和文化等方面。隨著計算機硬件的迅速發(fā)展，具有并行計算能力的破解技術(shù)日益成熟。僅通過增加加密算法的密鑰長度來達(dá)到增強安全性已不再是唯一的可行方法。但對信息隱藏而言，可能的監(jiān)測者或非法攔截者則難以從公開信息中判斷機密信息是否存在，難以截獲機密信息。
本論文將密碼編碼學(xué)和信息隱藏技術(shù)相結(jié)合，并通過人眼的視覺冗余來實現(xiàn)對24位位圖圖片文件的信息隱藏和還原。本系統(tǒng)是基于Windows XP環(huán)境下，通過Visual C＋＋6.0開發(fā)的。經(jīng)測試結(jié)果表明：通過該最低有效位（LSB）算法，能夠?qū)崿F(xiàn)在一副比如（40×40，4.74KB）的24位位圖中隱藏600個字節(jié)的信息，并且，圖片隱藏信息的能力與它自身的大小成正比。而通信雙方只能在輸入正確密鑰的情況下才能從載體圖片中提取出正確的秘密信息；否則得到的將是一堆亂碼。從而表明，將密碼編碼學(xué)和信息隱藏相結(jié)合使得秘密信息的通信得到了更高的安全的保障。
關(guān)鍵詞：信息安全；加密算法；信息隱藏；感覺冗余；最低有效位（LSB）

The Design of Information Hiding and Recovering in Image Files
Abstract
With the rapid development of information technology, network technology and electronic commerce, network information security will endanger the society such as economic, political and cultural fields, and so on. With the rapid development of computer hardware, nowadays the computers with parallel computing ability can crack information more and more easily. It is not the only option which to increase the key length of encryption algorithm in order to enhance security. On information hiding, it is difficult for the potential monitor or illegally interceptor to judge whether the confidential information exists in the open information or not.
This paper combined cryptography and information hiding technology, meanwhile through the seeing redundancy of eyes of mankind to achieve the hiding and recovering of 24 bitmap image files. The system is based on Windows XP and developed through Visual C + +6.0 for development tool. The Experiments recommend that the least-significant-bit(LSB) algorithm, can achieved such a (40 × 40. 4.74KB) 24 bits hidden in bitmap 600 bytes of information, Moreover, the ability of  hidden information is proportional to the size of picture. The tow sides of Communication who get the correct key can get the correct secret information from the Photo; otherwise, will be the piles of distortion.
So we can see that the combination of cryptography and information hiding makes the communication of information much more securely.

Key words: Information security; Encryption Algorithm; Information Hiding; Feeling redundancy; Least-significant-bit (LSB)

目  錄

1 引言 1
1.1 課題背景 1
1.2 信息隱藏技術(shù)在國內(nèi)外的發(fā)展及現(xiàn)狀 1
1.3 本課題研究的意義 2
1.4 本課題的研究方法 2
2 BMP位圖格式簡介 3
2.1 BMP簡介 3
2.2 BMP文件結(jié)構(gòu) 3
2.2.1 BMP文件組成 3
2.2.2 BMP文件頭 3
2.2.3 位圖信息頭 4
2.2.4 位圖數(shù)據(jù) 4
3 DES算法簡介 5
3.1 DES算法流程圖 5
3.2 DES解密 6
4 信息隱藏 6
4.1 信息隱藏簡介 6
4.2 信息隱藏特點 6
4.3 信息隱藏技術(shù)組成 7
4.4 早期的彩色圖像信息隱藏方法 8
4.5 LSB算法簡介 8
4.6 算法實現(xiàn)思想 8
4.7 主要算法流程圖及代碼 9
4.7.1 嵌入算法流程 9
4.7.2 提取算法流程 10
5 系統(tǒng)測試 12
5.1 運行結(jié)果 12
5.2 測試信息隱藏 12
5.3 測試信息還原 14
結(jié)    論 16
參考文獻(xiàn) 17
致    謝 18
聲    明 19