An Image Encryption Model Using, Brownian motion Intertwining Logistic Map and Coupled Map Lattice

  • Rajendra Kumara, Subodh Kumara


In the present scenario, multimedia encryption is the key challenge. The image itself is divided into red, green, and blue channels in most of the image encryption models or treated as a whole to design the shuffling algorithms. This results in low sensitivity and makes each channel separate.Mixing is used along with shuffling to reduce channel independence problem and to further  minimise sensitivity NPCR and UACI is used. This paper uses an intertwining logistic map-based shuffling, Brownian Motion-based confusion method and diffusion mechanism based on Coupled map lattice to investigate a cryptographic mechanism. First, the model decomposes the colour image into a single array and mixes it with a pseudo random number and then shuffles it using an intertwining shuffling engine based on a logistic map. The process of uncertainty based on Brownian motion increases key sensitivity. Finally, a Coupled Map-based diffusion changes pixel values in a way which affects most pixel values in a resulting cypher by changing the pixel value minute enough. Key streams used in confusion and diffusion are made based on plain images that follow the symmetric encryption model requirements. The final outcome suggests that a colour picture can be encrypted into a random binary sequence by the proposed encryption model. This increases image protection and the required NPCR and UACI values. In the generated cipher, the correlation coefficients between pixels are found to be negligible. The model is found to be resistive against various attacks of differential, statistical and brute-force.