Image encryption algorithm based on image hashing, improved chaotic mapping and DNA coding

Abstract

In order to improve the problems of security and robustness for existing image encryption algorithms and to reduce the security risks of encryption algorithms against statistical analysis, differential attacks, exhaustive attacks, cropping and noise attacks etc., a novel image encryption algorithm based on image hashing, improved chaotic mapping and DNA coding is proposed. Firstly, extracting the image features and evenly block after pre‐processing the original image and fingerprint image. Secondly, the features are generated to be a binary hash sequence through the image hash algorithm, and the generated hash sequence is iterated as the initial parameter of the improved chaotic map and Chen's chaotic system. Finally, Chen's chaotic system is used to generate a random sequence, and the matrix generated by the improved chaotic map and the original image is subjected to DNA calculation and encoding operations to obtain an encrypted image. Experimental results show that the proposed algorithm has better performance on security, larger key space and higher key sensitivity, the pixel correlation coefficient close to 0, the information entropy close to 8, unified average changing intensity and number of pixels change rate values are close to ideal values, and it has better robustness on noise and cropping attacks.