一种基于混沌映射与S盒的Feistel结构图像加密算法

Feistel Network Image Encryption Algorithm Based on Chaotic Map and S-box

计算机网络的发展和数字信息的多样化对信息保密技术提出了新的要求,人们在已有的加密算法的基础上开始着手研究新的加密方法以满足不同类型数据的保密要求。针对图像数据将分组密码学中的交替结构首先引入到基于混沌映射的图像加密系统中,采用混沌映射进行像素的置换和扩散,将动态S盒用于像素替代,两种操作交替执行。在每一轮加密中,通过简单的密钥扩展产生多个子密钥,分别用于不同的子加密过程。最后,理论分析和仿真结果表明,该加密算法具有严格的雪崩效应,且扩散性能和扰乱性能理想,能够有效地抵抗差分、统计分析和选择性明文攻击。

With the developing of the computer network and the diversifying of the digital information, it has put forward new challenge to the technology of the information secrecy because the traditional encryption method can not meet the requirement. The research was made to find new encryption algorithm for special data. A novel feistel network image encryption algorithm was proposed based on chaotic map and dynamical S-box. In each round of encryption, firstly chaos maps were employed to permute and diffuse pixels, then the dynamical S-box was used for pixels substitution. Sub-keys generated via simple extension of secret key was applied for different sub-encryption process respectively. Theoretical analysis and simulated experiment show that the proposed algorithm is very sensitive to initial condition and the diffusion and confusion properties of the algorithm are very ideal. The scheme can effectively resist differential analysis, statistic analysis and chosen plain image attack.