以中國餘式定理實作影像分享之研究

Implementation of Image Sharing Based on Chinese Remainder Theorem

莊廷偉(Ting -Wei Chuang)

指導教授 ： 陳朝欽

國立清華大學/電機資訊學院/資訊系統與應用研究所/碩士(2015年)

摘要

由於資訊科技快速發展，像是軍方影像、商業報告等機密資訊透過不安全的管道傳遞成為了一個富有挑戰性的安全議題，影像分享是一個能用來保護我們秘密影像的有用方法，根據(k, n)門檻方法，這項技術將秘密影像分成n張子影像並由n個參與者保存，而不是傳統的一個攜帶者，假如我們收集到k張的子影像就可以還原出秘密影像，如果只收集到少於k張的子影像，則無法還原秘密影像。
在本論文中，運用中國餘式定理，我們實作了一個影像分享及還原系統，並使用了一個基本的互斥或(XOR)加密法來加密我們的像素值，所以任何想要還原出秘密影像需要擁有加密過程中使用的鑰匙(key)。在我們所提出的方法中，我們僅能還原出一個與秘密影像相差一位元的失真影像，然而，肉眼並無法出其與秘密影像只有一個位元的差異。

關鍵字

影像分享

並列摘要

Due to the fast growth of information technology, the transmission of sensitive information such as military images, commercial reports etc. over insecure communication channels causes a challenging security issue. The image sharing is a useful method to protect our secret images. Based on (k,n) threshold scheme, this method distributes the secret image into n shadow images which are preserved by n participants instead of only a single carrier. If we collect at least k shadow images, we can reveal the secret image. Fewer than k shadow images cannot reveal the secret image.
In this thesis, we implement an image sharing and revealing system by the mechanism of Chinese remainder theorem. We encrypt the pixel values using the simple exclusive-or (XOR) cipher, so anyone who wants to reveal the secret image must own the key in encryption. In our proposed method, we can only reveal a distortion image with the least significant bit loss. However, naked eyes cannot distinguish the difference between the secret image and distortion image with only the difference of the least significant bit.

並列關鍵字

Image Sharing

參考文獻

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[Shyu2008] S.J. Shyu and Y.R. Chen, “Threshold Secret Image Sharing by Chinese Remainder Theorem,” IEEE Asia-Pacific Services Computing Conference, 1332-1337, 2008.

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[Trap2006] W. Trappe and L.C. Washington, Introduction to Cryptography with Coding Theory, Pearson International Edition, 2006.