資料隱寫技術及其應用之研究

Some Data Hiding Techniques and Their Applications

許泰榕(Tai-Jung Hsu)

指導教授 ： 張真誠

國立中正大學/工學院/資訊工程學系/碩士(2013年)

摘要

隨著近年來網際網路的蓬勃發展，數位資訊傳輸也因此變得更加地頻繁，如何確保數位資料在網際網路傳輸時的安全性也變得越加重要，所以，能夠有效率並且可以保護數位資料的方法是迫切需要的。資訊隱藏就是因應資訊安全需求所產生的一門研究， 其衍生的相關研究技術諸如隱寫學、可回復式資訊隱藏、易碎型浮水印、機密共享......等等。一般著名的資訊隱藏技術，主要是藉由將機密資訊藏入用來偽裝的媒介上，例如影像、影音或者文件， 讓攻擊者不易察覺其特異之處，藉以躲避惡意的攻擊或竄改，達到資訊安全的目的。

在本篇論文裡，我們提出了兩個可回復式資訊隱藏的方法，以及一個易碎型浮水印的方法。其中一個可回復式資訊隱藏的方法利用了兩個直方圖統計的結果來進行資訊隱藏，並且可以避免不足位/溢位的問題。而另外一個則是利用了開發修正方向的方法以及兩張偽裝影像來達到可回復式資訊隱藏。最後我們也提出了一個藉由最高有效位元以及參照位元來分別產生認證位元的易碎型浮水印方法，來提高回復被竄改之後影像的效能。

關鍵字

易碎型浮水印 ； 可回復式資訊隱藏 ； 隱寫學 ； 資訊隱藏 ； 開發修正方向

並列摘要

As a consequence of the prevalence of the Internet in recent years, the transmission of digital information has become much more frequent. Thus, it has become very important to identify methods that ensure the security of the digital information that is transferred on the Internet. Extensive research has been conducted on data hiding techniques in order to accomplish this goal, as evidenced by the various techniques that have been proposed, e.g., steganography, reversible data hiding, fragile watermarking, and secret sharing. Normal data hiding is a technique that usually hide the secret information in the cover media, such as an image, a video, or a text file. This approach makes it difficult for a malicious attacker to perceive that information is hidden in the medium, thus it is unlikely that an attack or tampering with the information will occur, so the aim of transmitting private information securely is achieved.

In this thesis, we proposed two reversible data hiding methods, and a fragile watermarking scheme. One of the reversible data hiding methods uses dual-histograms to embed the secret data, and to avoid underflow/overflow problems. The other reversible data hiding method uses the exploiting modification direction (EMD) and two steganographic images to reach the goal of reversibility. We also proposed a fragile watermarking scheme that generates authentication bits respectively by using the most significant bits (MSBs) and the reference bits, to enhance the recovery performance after a tamper attack has been encountered.

並列關鍵字

Fragile warermarking ； Reversible data hiding ； Steganography ； Data hiding ； Exploiting modification dircetion

參考文獻

[1] R. L. Rivest, A. Shamir, L. Adleman, A method for obtaining digital signatures and public-key cryptosystem, Communications of the ACM, vol. 21, no. 2, pp. 120-126, 1978.

[2] H. J. Highland, Data encryption: a non-mathematical approach, Computers and Security, vol. 16, no. 5, pp. 369-386, 1997.

[3] J. Tian, Reversible data embedding using a difference expansion, IEEE Transactions on Circuits and Systems for Video Technology, vol. 13, no. 8, pp. 890-896, 2003.

[4] A. M. Alattar, Reversible watermarking using the difference expansion of a generalized integer transform, IEEE Transactions on Image Processing, vol. 13, no. 8, pp. 1147-1156, 2004.

[6] D. M. Thodi and J. J. Rodriguez, Expansion embedding techniques for reversible watermarking, IEEE Transactions on Image Processing, vol. 16, no. 3, pp. 721-730, 2007.