基於各種拼圖遊戲的資訊隱藏學之研究

在網際網路上有許多種不同的拼圖遊戲。在本篇論文裡面，我們提出三個新的資訊隱藏方法，分別將秘密資訊藏在三種熱門的拼圖遊戲中：jigsaw拼圖、jig swap拼圖和 (n2-1)拼圖。我們所提出的第一個新方法，是將秘密資訊藏在 jigsaw拼圖影像裡面。首先，將一個輸入的數位影像分割成許多區塊(blocks)。接著，在每一個區塊的右邊跟底部畫上一個半圓(semicircle)並與邊線相接。我們將利用半圓的位置和圓弧的方向和一把秘密金鑰(stego-key)來藏秘密資訊。最後會得到一個看起來像一般常出現在網路上之jigsaw拼圖影像。第二個提出的新方法，是將秘密資訊藏在jig swap拼圖影像裡面。首先，將輸入的一個彩色數位影像分割成許多區塊。然後將每個區塊根據秘密資訊和一把秘密金鑰，重新規劃擺到新的位置。最後會得到一個完美的jig swap拼圖影像。解密的過程將需要原始影像。假設，發信者(sender)跟收信者(receiver)分享一些共同的影像，收信者將可以從已藏有秘密資訊的jig swap拼圖影像中擷取出藏入的秘密資訊。第三個提出的新方法，是將秘密資訊藏在一個可解的(n2-1)拼圖裡面。秘密資訊一開始將被轉換成一個從1到n2-1數列的排列。接著基於一parity測試演算法及一秘密金鑰，我們提出一偶排列產生器，將秘密資訊轉換出來的排列轉換成一個可解的(n2-1)拼圖。我們同時也提出一個如何利用線上拼圖遊戲 (on-line puzzle game) 來傳輸秘密資訊的方案。實驗數據顯示出我們所提出的三個資訊隱藏方法都是不可被偵測的 (undetectable)。更進一步來說，第一和第二個所提出的方法，都是對失真壓縮 (lossy compression) 和壓縮格式轉換 (format conversion)具有抗性；第三個方法則是沒有失真壓縮、壓縮格式轉換和幾何圖形失真的問題。

關鍵字

資訊影藏學；拼圖遊戲；資料藏匿

並列摘要

There are many kinds of puzzle games on the Internet. In this thesis, three new steganographic methods are proposed based on three popular puzzle games: jigsaw puzzle, jig swap puzzle and (n2-1)-puzzle. The first novel method is proposed to hide secret data in jigsaw puzzle images. First, a digital image is taken as input and divided into blocks. Then, a semicircle is drawn and attached to the right/ bottom side of each block. The secret data are embedded through the attached positions and orientations of the semicircles according to a stegokey. The resulting image looks like those jigsaw puzzle images appearing on many jigsaw puzzle Web sites. The second novel method is proposed to hide a secret message in a jig swap puzzle image. First, a color image is taken as input and divided into blocks. Second, each block is rearranged to a new position according to the secret data and a stegokey. The resulted image is a perfect jig swap puzzle. The original image is needed for extracting secret data. Under the assumption that the receiver and the sender share some common images, the receiver can extract the secret data from the jig swap puzzle image. The third novel method is proposed to hide secret message in a solvable (n2-1)-puzzle. The secret message is first converted into a permutation of numbers 1 to n2-1. Based on a parity test algorithm and a stegokey, an even permutation generator is provided to transform the obtained permutation into a solvable stego-(n2-1)-puzzle. A scenario is also presented for secret message transmission via an on-line puzzle game. Experimental results show that all of these three proposed methods are undetectable. Furthermore, the first and second methods are robust to lossy compression and format conversion, and the third method has no robustness problem for lossy compression, format conversion and geometric distortion.

並列關鍵字

steganography ； puzzle games ； data hiding

參考文獻

[Bend1996] W. Bender et al., “Techniques for Data Hiding,” IBM Systems J., Vol. 35, No. 3-4, 313-336, 1996.

[Chan2002] C. L. Chang, T. S. Chen, and L. Z. Chung, "A steganographic method based upon JPEG and quantization table modification," Information Sciences, Vol.141, No.1-2, 123-138, 2002.

[Chan2004] C. K. Chan and L. M. Cheng, “Hiding data in images by simple LSB substitution,” Pattern Recognition, Vol. 37, 469–474, 2004.

[Delf2008] A. Delforouzi, M. Pooyan, “Adaptive digital audio steganography based on integer wavelet transform,” Circuits, Systems, and Signal Processing, Vol. 27, No. 2, 247-259, 2008.

[Dema2007] E. D. Demaine and M. L. Demaine, “Jigsaw puzzles, edge matching, and polyomino packing: connections and complexity,” Graphs and Combinatorics, Vol. 23, No. 1, 195-208, 2007.

國際替代計量

基於各種拼圖遊戲的資訊隱藏學之研究

全文下載

主題瀏覽