双向扩散机制融合时间延迟的图像加密算法.pdf

40 7 2014 7 Vol.40 No.7 Computer Engineering July 2014 1000-3428(2014)07-0225-05 A TP391 1 2 2 (1. 621000 2. 610065) LORENZ logistic Image Encryption Algorithm for Bilateral Direction Diffusion Mechanism Integration with Time Delay 1 2 2P P P WANG Fu , ZHENG Ya-ping , LIU Tian-qi (1. School of Mathematics and Computer Science, Mianyang Normal University, Mianyang 621000, China; 2. School of Electrical Engineering and Information, Sichuan University, Chengdu 610065, China) Abstract To defects such as the low speed of encryption and decryption, as well as the low computation efficiency induced by the single diffusion mechanism in the current chaotic-based encryption system, the high autocorrelation of chaotic sequence is induced by ignoring the time delay, resulting in the misadventure performance of encryption quality, low security, as well as not satisfying the security and real-time transmission in the face of high resolution, large capacity image. The time delay function and bilateral direction diffusion mechanism are proposed, using the fast image encryption algorithm based on bilateral direction diffusion mechanism integration with time delay to solve above problems. The hyper-chaotic LORENZ system is iterated to get one group hyper-chaotic sequence. The time delay is introduced into the hyper-chaotic sequence by the time delay and logistic map to obtain the new sequence. The permutation method of position set is used to permute the pseudo-random sequence on the time