In modern technological era image encryption has become an attractive and interesting field for researchers. They work for improving the security of image data from unauthorized sources. Chaos theory, due to its randomness and unpredictable behaviors, is considered favorite for the purpose of image encryption. This paper proposes a diffusion based image encryption algorithm by using chaotic maps. Firstly a chaotic map (piecewise linear chaotic map) is used for the generation of S-box, then it is used for the pixel values modification to generate element of non-linearity. After this these modified values are further diffused with another random sequence, generated by tent logistic chaotic map. Finally the color components of pre-encrypted image are mixed with each other so that the developed randomness uniformly distributed in them. For image data we develop non-linearity and diffusion by using S-box and then more randomness is added in the pre-encrypted image with the help of Boolean operation XOR. The use of this combination of chaotic maps along with S-box and Boolean operation XOR is a different technique, that provides satisfactory results for security aspects and also works efficiently.
Keywords: Chaos; Chaotic system; Image encryption; Piecewise linear chaotic map; S-box; Tent logistic map.
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022.