A color image cryptosystem based on dynamic DNA encryption and chaos

Abstract

• A color image cryptosystem based on dynamic DNA encryption and a four-wing hyperchaotic system is presented. • Dynamic DNA encoding and decoding rules for all the pixels are generated and dependent on the plain image. • A novel diffusion mechanism based on random numbers related to plaintext (DMRNRP) is introduced to diffuse the DNA sequences of the plain image. • The image encryption method is highly sensitive to the plain image. • Experimental results demonstrate that the proposed encryption algorithm has good security performance. This paper presents a color image cryptosystem based on dynamic DNA encryption and chaos. The color plain image is firstly decomposed into red, green and blue components, and then a simultaneous intra-inter-component permutation mechanism dependent on the plaintext (SCPMDP) is introduced to shuffle them. Secondly, convert the recombined permutated components into a DNA matrix by a DNA encoding rule, and subsequently, different from the traditional DNA sequence operations according to the law of binary calculation, a diffusion mechanism based on random numbers related to plaintext (DMRNRP) is presented to diffuse it. Further, transform the diffused DNA matrix into a decimal one according to a DNA decoding rule, and divide it into three equal images. Finally, to enhance security of the image cryptosystem, the second confusion scheme is applied to respectively scramble images, and the color cipher image is gotten. A four-wing hyperchaotic system is used to provide pseudo-random chaotic sequences, SHA 384 hash function of the plain image and external parameters are combined to compute its initial values, and one-time-pad encryption policy makes the proposed encryption effectively resist plaintext attacks. Experimental results and security analysis demonstrate that our encryption algorithm has good performance and may resist against various typical attacks.