Abstract: The fractional Logistic chaotic map has a simple form but holds complex dynamic behavior and can be readily generated on computer. In this paper, an image encryption algorithm is proposed by using the map and DNA coding. The fractional chaotic map generates a key chain. Each pixel layer of the RGB image is encrypted through changing pixel locations. A gray scale image is obtained by combination of the three encryption results. The encrypted image not only changes the size of the original image but the type. Through the security analysis including key sensitivity, statistics and correlation analysis, the results show that the algorithm has good robustness, key sensitivity and enhanced the key space and leads to high security.

Key words: Chaos, Fractional Logistic map, Image encryption, DNA sequence