基于双延迟变形系统的图像加密方法

针对典型的超混沌序列伪随机性较差的问题, 提出了一种基于掺铒光纤激光器双延迟变形系统超混沌序列的图像加密方法。该方法使用改进的双延迟变形系统产生超混沌伪随机序列, 该序列有更大的李雅普诺夫指数, 更强的伪随机特性。该方法应用在图像加密上, 只需一轮置乱和扩散, 并且不用同其他的伪随机序列联合使用。实验证明, 该方法有可靠的安全性, 足够的密钥空间和可接受的加密速度。

Image Encryption Scheme Based on Double-Delay Reforming System

To resolve the problem of typical characteristics of hyperchaos sequence with weak pseudo random,an algorithm based on double-delay reforming system is proposed.The sequence which produced by double-delay reforming system has larger Lyapunov exponent and better paseudo-random characteristics than that of the previous hyperchaos system.Without other combined pseudorandom sequences,only one total round of substitution and diffusion can meet good effect.Simulation result shows that the suggested algorithm satisfies the required performance tests such as high level security,large key space and acceptable encryption speed.