臺灣博碩士論文加值系統

藏密學是一門關於資訊隱藏的理論。主要的目的在於避免訊息在傳遞過程中遭受竊取或破壞。這篇論文提出了一個具有高容量的藏密系統，我們採用基於MRF 模型的紋理合成演算法 [Chen2003] ，合成
出符合使用者需求大小的載體影像。一般情況下，隱藏訊息的長度受
限於載體影像的大小，而我們採用紋理合成的方法來解決這個問題。
此外，為了增加藏密的安全性，在訊息被嵌入至載體影像之前，我們
會先對其進行加密的動作，而我們所採用的加密方法是基於數論中原
根的特性。當

Steganography is a theory of information hiding. It prevents secret message from being stolen and destroyed during communication. This thesis proposes a high-capacity steganographic system for data hiding. We adopt a texture synthesis algorithm based on Markov Random Field (MRF) model [Chen2003] to synthesize cover images with user-selected size. Generally, the length of a secret message to be
hidden is limited by the size of the cover image; we solved this problem by using the texture synthesis algorithm. In addition, to enhance the security, we encrypt the secret
message before embedding it into a cover image. The encryption method is based on the property of primitive root mentioned in Number Theory. When

Chapter 1 Introduction..........................1
Chapter 2 Background Review.....................4
2.1 Markov Random Field.................4
2.2 Generalized Ising Model (GIM).......6
2.3 Some Theorems from Number Theory....7
Chapter 3 Proposed Data Hiding Method...........9
3.1 Motivation..........................9
3.2 Cover Image Generation..............9
3.3 Encryption.........................10
3.4 Embedding..........................11
3.5 Extracting.........................12
Chapter 4 Experimental Results.................14
Chapter 5 Conclusion and Future Work...........22
References.....................................23

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[Chan2011] F.J. Chang and C.C. Chen, “A Steganographic Method Using MRF-Synthesized Textures as Cover Images,” The 4th International Workshop on Image Media Quality and Its Applications, 58-62, 2011.
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