基於適應性資訊隱藏技術之光學彩色影像加解密系統研究

A Study on Adaptive Steganography-based Optical Color Image Cryptosystem

曾信淳(Hsin-Chun Tseng)

指導教授 ： 莊政宏

亞洲大學/資訊學院/資訊工程學系碩士班/碩士(2010年)

摘要

本論文提出一種基於適應性資訊隱藏技術之光學彩色影像加密系統，在此光學加密系統中，可以將一張秘密的彩色影像當作相位資訊嵌入到大小相同的主要影像中成為偽裝影像，此偽裝影像經由雙隨機相位演算法編碼，並且以資訊隱藏技術嵌入密碼後可得到一張加密偽裝影像。如此即可完成機密影像及資料的傳輸，並可達成對於主要影像的加密保護作用。
在資訊隱藏技術的部分，主要探討彩色影像RGB三色頻分離及合併處理方式，同時比較固定區域及適應性資訊隱藏的兩種方法。固定區域隱藏的方式是將機密資料藏匿在固定區域，而適應性資訊隱藏則為動態隱藏方式，根據影像內容找出較佳隱藏位置。由實驗中發現，本論文所提出之彩色影像色頻合併處理方式，並且以適應性資訊隱藏技術進行資料藏匿，可提供較大的資料隱藏量並可取得更好的重建影像品質。最後在實驗中以模擬攻擊的方式，進行訊號遭受攻擊時之分析與探討。

關鍵字

資訊隱藏 ； 資訊安全 ； 影像加密 ； 藏密學 ； 浮水印 ； 雙隨機相位

並列摘要

In this thesis, an optical color image cryptosystem with a color image and data hiding scheme is proposed. In the proposed optical cryptosystem, a secret color image is embedded into host image of the same size to become a stego-image. The secret color image is hidden in the phase term of the host image. Then the stego-image is encrypted by the optical cryptosystem which employs a double random phase encoding algorithm. During the encoding process, secret data is embedded into the encrypted image by an adaptive steganographic technique. The secret image and data delivery is accomplished by hiding the image into the host image and embedding the data into the encrypted stego-image. In comparison with the traditional hiding scheme, a high data embedding capacity and high visual quality of the decrypted host and secret images are achieved. Experimental results show that the proposed image and data steganographic cryptosystem provides large data hiding capacity and high reconstructed image quality.

並列關鍵字

Data Embedding ； Data Hiding ； Information Security ； Image Encryption ； Steganography ； Watermarking ； Double Random Phase

參考文獻

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