基于超混沌系统和密文交错扩散的图像加密新算法

New Image Encryption Algorithm Based on Hyperchaotic System and Ciphertext Diffusion in Crisscross Pattern

该文提出一种基于超混沌系统优化序列并结合密文交错扩散的并行图像加密策略。首先,对超混沌序列进行改造使得改进序列更适合图像加密;然后,利用改进的混沌序列产生与明文相关的最终密钥序列,使得算法对明文敏感。图像被分成两个子块,以并行方式对子块进行两轮像素加密,并引入密文交错扩散技术。对密钥空间和执行效率、像素分布特性、相关系数、抗差分攻击能力以及密钥敏感性进行了测试和分析,证明了方案的安全性和执行效率。结果表明,该算法安全高效,在图像保密通信中具有较大的应用潜力。

A new image parallel encryption strategy is proposed based on the improved hyperchaotic sequences and ciphertext diffusion in crisscross pattern. Firstly, the hyperchaotic sequences are modified to generate chaotic key stream that is more suitable for image encryption. Secondly, the final key stream is generated by correlating the chaotic key stream and plaintext which result in both key sensitivity and plaintext sensitivity. The plain-image is firstly divided into two sub-images, then sub-images are encrypted simultaneously in a parallel manner with two rounds. The technology of ciphertext diffusion in crisscross pattern is introduced. Performance test and security analysis are performed using key space analysis and algorithm efficiency test, the pixels distribution character, correlation coefficients, the ability to resist differential attack and key sensitivity test. Results suggest that the proposed image encryption scheme is secure and efficient, with high potential to be adopted for the secure image communication applications.