基于二维四值元胞自动机和混沌系统的图像加密算法

Image Encryption Algorithm Based on 2D Quaternary Cellular Automata and Chaotic System

提出了一种结合改进的Logistic-PWLCM映射、超混沌Chen系统所生成的改进序列和二维四值元胞自动机的图像加密方法。将Logistic映射和PWLCM映射复合得到新的一维混沌系统,利用该系统和超混沌Chen系统所生成序列的改进,使得用于控制加密过程的密钥流序列具有更好的混沌特性。论文构造了一个新型的二维四值元胞自动机,对传统的二值元胞自动机做了推广,提高了元胞自动机演化的复杂性。用该元胞自动机和两个混沌系统设计了一个新的混沌图像加密算法,并做了详细的性能分析。实验结果和分析显示,本文所提出的图像加密算法具有较大的密钥空间和抵御多种攻击分析的优良性能。

A chaotic image encryption algorithm which combines improved Logistic-PWLCM map, improved sequences generated by hyperchaotic Chen system and 2D quaternary cellular automata is proposed. In the proposed cryptosystem, Logistic map and PWLCM map are compound into a new map, and the sequences generated by hyperchaotic Chen system are improved, which makes the key streams controlling the encryption process have better chaotic nature. A new 2D quaternary cellular automata is constructed as well. The evolution complexity of the cellular automata is greatly enhanced. A new chaotic image encryption algorithm is designed using the proposed cellular au-tomata and two chaotic systems. Its security and performance are analyzed in detail. The experimental results and analysis show that the proposed image encryption algorithm has larger key space and good performances to resist various attacks.