A color image channel fusion encryption scheme combining a four-dimensional chaotic system

Compared with other forms of information communication, images have the advantages of high information density, strong visualization, strong emotional transmission, and cross-linguistic and cross-cultural. It can quickly convey a large amount of information, trigger emotional resonance, cross the language barrier and enhance memorization, which is an efficient way of information transmission. With the wide application of technologies such as social media, smart surveillance and biometrics, images cover a large amount of personal privacy and sensitive information. Image leakage or misuse may lead to serious consequences such as identity theft, privacy violation and even property loss. Currently, many image encryption algorithms encrypt RGB channels independently when encrypting color images. This method, although concise and clear, has some limitations. For example, it may leak the color distribution between channels, and lack of resistance to statistical attacks, and other defects. In summary, this paper proposes a channel fusion encryption scheme combined with a four-dimensional chaotic system to make up for the above limitations. The scheme is organized in three main parts: channel fusion, diffusion encryption and substitution encryption. First, the RGB channels from the original color image are fused into a sequence. Second, the sequence is subjected to diffusion encryption and substitution encryption respectively. The entire encryption model combines four-dimensional chaos and SHA-256 to increase the safety and robustness for the proposed method. After analyzing the safety, the scheme can efficiently realize the image encryption and effectively protect the privacy of the image.