A Novel Method for Image Encryption Using Chaotic Maps

With rapid intention of using computer networks as a media for communication, providing security for this media has gained attention of many researchers. Therefore, Image encryption methods are studied widely in order to provide secure platform for sharing images between end parties. In this paper, a novel approach for image encryption based on mixing chaotic maps is proposed. Two secret keys which are entitled CK , AK , used to make our scheme highly dependent to image. Indeed, if these values changed slightly, the result will be changed completely. In diffusion phase, combination of two high level chaotic maps that are Logistic-sinus and Power-Logistic used to build a chaotic matrix, which is possessed better chaotic behaviour. Finally, in permutation phase, produced index of two newfound high level chaotic maps are used to modify pixel positions. The proposed diffusion phase provides desirable uniformly distribution in color histogram of encrypted image and makes the scheme robust against statistical attacks. Furthermore, creating secret with high sensitivity to the original image leads to acceptable results in the average of NPCR (99.68), UACI (33.50), and resistance against brute-force attack. The experimental results prove that the image encryption scheme has the characteristics of secure encryption algorithm such as, large key space, high security and high sensitivity.

Keywords:

Chaos , NPCR , UACI , Security