An image encryption algorithm based on bit level Brownian motion and new chaotic systems

In this paper, a new image encryption algorithm based on Brownian motion and new 1D chaotic system is introduced. Firstly, SHA 256 hash value of the plain image is used to generate the initial values and system parameters of chaotic systems for confusion and diffusion process. Then, 8 bitplanes of the plain image are scrambled based on Brownian motion, respectively, and the position and value of all pixels are changed simultaneously. After the confusion process, a two directional diffusion process is carried out, and it is made up of row diffusion (RD) and column diffusion (CD). The whole process can be repeated many rounds in order to get better encryption effect. Simulation results and security analysis show that our scheme has properties of large key space, high sensitivity to key, strong resisting statistical and differential attack. So, it has high security and important practical application in image transmission and image encryption.