以混沌變數序列應用於影像像素位置之行列置亂加密

Pixel Shuffle for Color Image Encryption Based on Chaotic Variable Sequences

粘孝先(H.H. Nien) ； 張簡士琨(S.K. Changchien) ； 黃川桂(C.K. Huang) ； 鄧吉斌(C.P Teng) ； 詹智皓(C.H Chan)

《建國科大學報》 28卷1期 (2008/10) Pp. 1-12

https://doi.org/10.6995/JCTU.200810.0001

摘要

本文提出一個以三維混沌系統為基礎之像素置亂彩色影像加密方法。由於混沌系統之動態行為具有不可預測的特性，且對系統變數初值及變數參數改變非常靈敏，因此，將此混沌變數序列製作成密碼，應用於影像加密，可實踐具極高安全性的加密影像，可防止竊密者破解。本文應用MATLAB軟體，模擬三維Lorenz混沌系統，以此混沌系統產生混沌變數序列X、Y、Z，然後將此變數序列製作成三組加密陣列，對數位彩色影像之R、G、B灰階圖分別進行其像素位置之行、列位置置亂加密及解密。文中，以三個應用實例驗證本文所提出之方法優越的加密性能，最後並以相關係數及熵值檢測加密密碼之安全性能及加密後影像的高度機密性。由實際之數位彩色影像加密應用例顯示，本文所提出之方法，具有良好的加密性能及安全性。

關鍵字

像素置亂 ； 影像加密 ； Lorenz混沌系統 ； 混沌變數序列 ； 相關係數

並列摘要

This paper proposes a novel pixel shuffle method based on chaotic system for image encryption. Since the dynamic response of the chaotic system is sensitively to the initial values and parameters of chaotic variables, the chaotic trajectory is highly unpredictable. Therefore we conduct the chaotic sequences to implement encryption codes and then encrypt color images with highly confidential security. In this research, the computer simulation of Lorenz system is achieved by MATLAB. Based on the simulation results, we make three sets of encryption codes by way of the produced chaotic variable sequences X, Y, and Z. Afterwards, these encryption codes are applied to shuffle each pixel in R, G, and B grey images of the plaintext respectively. Eventually, empirical examples show that the proposed method applied in the encryption of digital color images can achieve higher confidential security. And also the statistic methods involving the correlation coefficient r and the entropy are adopted to test on the distribution of distinguished elements of variables for the encryption images. The experimental results show that the proposed method has the great encryption performance and achieves the high confidential security.

並列關鍵字

Pixel shuffle ； Image encryption ； Lorenz system ； Chaotic variable sequences ； Correlation coefficient