摘要
鉴于目前大多基于混沌序列的图像加密算法,其置乱与扩散阶段是完全独立的,用到不同的状态变量,且密钥流完全依赖于密钥算法,即密钥算法不变,对不同的明文进行加密,使用的密钥流完全是一样的,难以抵御明文攻击或者选择性明文攻击.而本文设计了一种具有动态可变的基于超混沌系统的加密算法.首先,对超混沌序列进行优化预处理,得到随机性更理想的混沌序列,其次利用优化预处理后的混沌序列创建与明文图像相关的动态可选序列,最后构建与动态序列相关的密钥用于图像加密.这样若明文与混沌序列发生微小的变化,都会带来完全不同的密钥流.通过仿真和大量的分析,结果证明该算法具有较好的安全性和较高的有效性.
In view of most of the current image encryption algorithm based on chaotic sequences,the permutation and diffusion procedures are completely independent,use different state variables,and the key stream is completely dependent on the key algorithm,namely,constant algorithm key words of different plaintexts are encrypted,using the key flow is the same,so it is difficult to resist the plaintext attack or selective plaintext attack.This paper has designed a dynamic encryption algorithm based on hyperchaotic system.In this paper,the system is pre-processed to obtain the ideal chaotic sequence which has the better randomness,and the dynamic alternative sequence associated with the plain image is constructed,the secret key related to the dynamic sequence is created,which is used for the permutation and diffusion processes of digital image.In the proposed algorithm,if plain image or the chaotic sequences has minor changes,it will result an entirely different key stream.Experimental simulations and a lot of cryptanalysis have been carried out,the results prove the superior security and high efficiency of the scheme.
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2016年第9期910-918,共9页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:61271407)资助项目
关键词
图像加密
混沌系统
超混沌系统
图像置乱
image encryption
chaotic system
hyperchaotic system
image permutation
