摘  要

本文研究了数字图像加密的关键技术，重点探讨了Arnold变换（空间域像素置乱）与AES加密算法（CBC模式）的综合应用。通过对Arnold变换的基本原理、置乱效果及其周期性进行深入分析，以及AES加密算法的工作原理、工作模式及其加密流程的探讨，本文提出了一种结合Arnold变换与AES加密算法的数字图像加密方案。该方案首先对图像进行Arnold变换以置乱像素位置，然后使用AES加密算法对置乱后的像素值进行加密，实现双重加密效果。

本文采用Python等编程工具进行实验验证，通过对比不同加密参数下的加密效果和解密精度，评估了方案的可行性和有效性。此外，本文还针对Arnold变换的加密周期性与安全性、AES加密算法在图像加密中的优化以及Arnold变换与AES加密算法的融合策略等难点问题进行了深入研究，并提出了一系列优化方法。最终，本文利用Python技术搭建了一个B/S结构下的网站，实现了数字图像加密的功能模块，采用MySQL数据库存储用户信息，保证了系统运行的高效稳定。

关键词：数字图像加密；Arnold变换；AES加密算法；CBC模式；Python技术

A B S T R A C T 

This paper studies the key technology of digital image encryption, and focuses on the comprehensive application of Arnold transformation (spatial domain pixel chaos) and AES encryption algorithm (CBC mode). Based on the thorough analysis of the basic principle, scrambling effect and periodicity of Arnold transformation, and discussing the working principle, working mode and encryption process of AES encryption algorithm, this paper proposes a digital image encryption scheme combining Arnold transformation and AES encryption algorithm. This scheme first transforms the image by Arnold to disrupt the pixel position, and then uses the AES encryption algorithm to encrypt the scrambled pixel value to realize the double encryption effect.

This paper uses Python and other programming tools for experimental verification, and evaluates the feasibility and effectiveness of the scheme by comparing the encryption effect and decryption accuracy under different encryption parameters. In addition, this paper also studies the difficult problems such as the encryption periodicity and security of Arnold transformation, the optimization of AES encryption algorithm in image encryption, and the fusion strategy of Arnold transformation and AES encryption algorithm, and proposes a series of optimization methods. Finally, this paper uses Python technology to build a website under B / S structure, realizes the functional module of digital image encryption, and uses MySQL database to store user information, to ensure the efficient and stable operation of the system.

Key words: digital image encryption; Arnold transformation; AES encryption algorithm; CBC mode; Python technology