Journal of Computer Applications ›› 2026, Vol. 46 ›› Issue (1): 152-160.DOI: 10.11772/j.issn.1001-9081.2025010043

• Cyber security • Previous Articles     Next Articles

Image encryption algorithm based on cascaded chaotic system and filter diffusion

Mengmeng LI, Jiaxin HUANG, Jiawen LI, Shanshan LI()   

  1. School of Information Engineering,Chang'an University,Xi'an Shaanxi 710064,China
  • Received:2025-01-13 Revised:2025-03-16 Accepted:2025-03-17 Online:2026-01-10 Published:2026-01-10
  • Contact: Shanshan LI
  • About author:LI Mengmeng, born in 2002, M. S. candidate. Her research interests include image encryption, image processing.
    HUANG Jiaxin, born in 2000, M. S. His research interests include image processing, image encryption.
    LI Jiawen, born in 2000, M. S. candidate. Her research interests include image encryption.
  • Supported by:
    National Natural Science Foundation of China(61402051)

基于级联混沌系统和滤波扩散的图像加密算法

李萌萌, 黄佳鑫, 李佳文, 李珊珊()   

  1. 长安大学 信息工程学院,西安 710064
  • 通讯作者: 李珊珊
  • 作者简介:李萌萌(2002—),女,陕西渭南人,硕士研究生,CCF会员,主要研究方向:图像加密、图像处理
    黄佳鑫(2000—),男,陕西西安人,硕士,主要研究方向:图像处理、图像加密
    李佳文(2000—),女,陕西宝鸡人,硕士研究生,主要研究方向:图像加密
  • 基金资助:
    国家自然科学基金资助项目(61402051)

Abstract:

In response to the problems of small existing chaos system parameter range and poor diffusion effect of the encrypted algorithm, a new cascaded chaotic system and a filter diffusion model were designed, and a color image encryption algorithm with unlimited image size was proposed and implemented. Firstly, a chaotic system named 2D-SIHC (Two-Dimensional Sine-Iterative-Henon Chaotic system) of was proposed with Henon mapping, Sine mapping and Iterative mapping as seed mappings, and a linear function was incorporated to extend the parameter range. In the two-dimensional sequence generated by this system, one dimension was employed to disturb pixel positions, the other dimension was applied to update filter templates and perform diffusion operations. Secondly, in order to avoid key reuse that reduces the algorithm’s security, the SHA-512 algorithm was combined with plaintext images to generate the key through the calculation of flag bits and weights. Thirdly, in order to enhance the algorithm's diffusion effect, a two-dimensional filter diffusion model was designed. Different from the traditional filter diffusion, which altered image pixel values by fixed template traversing, image pixel values were modified by the new diffusion model dynamically in the way of introducing chaotic sequences to update filter template values continuously. Finally, encryption was realized. Experimental results show that,taking the Airplane image as an example, the proposed algorithm can achieve the Number Pixel Change Rate (NPCR) of 99.605 9% and the Unified Average Change Intensity (UACI) of 33.397 1%, respectively, which are very close to the ideal values. In addition, the algorithm can resist a noise interference with 0.2 intensity and a cropping attack with 50% missing,and it has high encryption efficiency.

Key words: image encryption, cascaded chaotic system, chaotic iteration, filter diffusion, key sensitivity

摘要:

针对现有混沌系统参数范围小以及加密算法扩散效果不佳的问题,提出一种新型级联混沌系统和滤波扩散模型,并实现一种不限图像尺寸的彩色图像加密算法。首先,设计一种新的二维级联Henon映射、Sine映射和Iterative映射的混沌系统(2D-SIHC),同时加入线性函数扩展参数范围。在该系统迭代生成的二维序列中,一维用于置乱像素位置,另一维用于更新滤波模板和扩散操作。其次,为避免密钥重复使用导致算法安全性降低的问题,使用SHA-512算法结合明文图像,通过标志位与权重的计算生成密钥。再次,为了增强算法的扩散效果,设计二维滤波扩散模型,不同于传统滤波扩散通过固定模板遍历改变图像像素值,新扩散模型引入混沌序列以不断更新滤波模板值,从而动态改变图像像素值,最后完成加密。实验结果表明,以Airplane图像为例,所提算法的像素变化率(NPCR)和统一平均变化强度(UACI)可以分别达到99.605 9%和33.397 1%,非常接近理想值;此外,所提算法能抵抗强度为0.2的噪声干扰和缺失50%的裁剪攻击,且加密效率高。

关键词: 图像加密, 级联混沌系统, 混沌迭代, 滤波扩散, 密钥敏感性

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