关键词: 小波变换, 图像加密, 混沌系统, 重力模型

Abstract: With the application and development of network technology, the security of image data has been aroused the attention of the whole society. A new image encryption algorithm based on wavelet transform and improved gravity model is proposed. The algorithm uses SHA3-256 to generate the initial value of the 3D Logistic chaotic system and the gravity coefficient of improved gravity model. The algorithm is closely related to the original image, which increases the plaintext sensitivity of the algorithm. Then it transforms the image by wavelet transform, uses 3D Logistic chaotic system to scramble the low frequency coefficient and the high frequency coefficient respectively. After the inverse wavelet transform, it uses improved gravity model to substitute pixel value. The experimental results show that the algorithm has a large key space and can effectively resist all kinds of attacks.

Key words: wavelet transform, image encryption, chaotic systems, gravity model