Lossless chaotic color image cryptosystem based on DNA encryption and entropy

Abstract

Based on deoxyribonucleic acid (DNA) coding and two excellent low-dimensional chaotic systems, a new color image cryptosystem is proposed in this paper. The presented image cryptosystem consists of four processes: key streams generation process, DNA sequences confusion process, DNA sequences diffusion process and pixel-level diffusion process. In the first stage, two simple improved chaotic systems and the information entropy of the plain-image are together employed to generate the pseudorandom key streams. Then, the original image is converted into the DNA sequence matrices by the DNA encoding rules, and the binary key streams are used to permute the DNA matrices. The third process performs a row and column diffusion processes on the scrambled DNA matrices by the key streams and DNA XOR operation. Finally, the DNA matrices are transformed into the encrypted image via the DNA decoding rules, and a ciphertext diffusion in crisscross pattern is further adopted to strengthen the security and sensitivity of the cryptosystem. Thus, the resulting cipher-image is obtained. Experimental results and security analysis have demonstrated the excellent performance of our proposed algorithm in image encryption.