用於影像、文件及網頁的資訊隱藏

Abstract

網路的蓬勃發展為人們帶來相當大的便利性，透過網際網路，人們可以互相傳遞訊息、找尋需要的資料、甚至於公布資訊，但是也由於公開的網路環境，非法者可以輕易地攔截秘密訊息、在未經擁有者允許之下使用網頁內的影像或是資料，或是更改公布的資訊而造成閱讀者的誤解。因此，本論文研究利用資訊隱藏的方法，針對網頁影像、中文字性文件以及網頁文件提出秘密通訊、版權保護以及竄改驗證三種應用。在秘密通訊方面，我們將秘密訊息分別隱藏於網頁影像、文件以及網頁之中，並且安全地將之傳送。在版權保護方面，我們將版權資訊隱藏於網頁文件中以保護擁有者的版權。不同於直接隱藏版權資訊，我們提出一種新的浮水印技術能夠在影像被下載的時候，主動地保護影像上造出一可視版權資訊來保護其版權。對於網頁內容是否遭受到竄改的部分，我們提出了一個驗證網頁內容真實性的方法。相關的實驗結果可證明我們所提方法的可行性。

The advance of computer network brings convenience to people. Through the Internet, people can transmit messages to each other, search desired data, or announce public information easily. But in the public network environment, illegal users can detect and intercept secret messages, misuse Webpage images or contents, or tamper with publications on Web pages, resulting in misrepresentation of them. Therefore, effective methods for three applications, including covert communication, copyright protection, and tamper proofing, on Webpage images, Chinese text-type documents, and HTML files are proposed in this study. For covert communication, secret messages are embedded into Webpage images, text-type documents, and HTML files by data hiding techniques, respectively. With imperceptible modifications of these media, the hidden secret can be transmitted securely. For copyright protection, copyright data are embedded into HTML documents to protect the intellectual property of their contents by text steganographic techniques. Instead of embedding copyright data directly, it is proposed in this study to embed an active data stream into a Webpage image to create actively a visible copyright logo onto a protected image when the image is downloaded. For tamper proofing of Web page content, an authentication signal generation and embedding method is proposed for verifying whether or not the content has been tampered with. Good experimental results show the feasibility of the proposed methods.