A Self-Adaptive Image Encryption Scheme Based on Chaos and Gravitation Model

In order to improve the security of image transmission, this paper proposes a self-adaptive image encryption scheme based on chaos and gravitation model. The proposed scheme consists of three stages: key generation stage, double scrambling stage, and double diffusion stage. In the key generation stage, the plaintext-associated key generation mechanism (BPPAKG) based on the bit plane is used to obtain the key associated with the plaintext. Since the key ultimately depends on the plaintext image itself, this scheme has self-adaptability. The first stage of scrambling uses mixed chaotic transform and shift row transform to disturb pixel position, then changes the pixel value of the image based on the concept of gravitation to achieve the first stage of diffusion. To enhance the security performance of the scheme, the traditional encryption structure is extended, and the second stage of scrambling and diffusion is quickly realized by using diagonal scanning transform and XOR operation. Simulation and experimental results show that the scheme has good encryption and decryption performance and strong resistance to attack. In addition, compared with some latest proposed algorithms, it has better security.