Triple chaotic image scrambling on RGB - a random image encryption approach

Multimedia is ruling the digital era where data storage and transmission have gained huge importance. The refuge of such data transfer has been a chief apprehension and becomes the study in the limelight, probably, forever. The universal phenomenon is to send the desired data in disguise so that only the beneficiary can avail it. In this paper, a combination of space-filling curve with chaos has been used for encryption process. Initially, three chaotic sequences were generated using Chua's equations followed by quantification of those sequences. Key based on Hilbert curve is used for scrambling. For introducing confusion, the image is further scrambled using row and column shifting operations using the first two chaotic sequences used with space-filling curve. Then pixel replacement has been done by bit XOR between scrambled image and the third chaotic sequence. Finally, Gould transform is applied to enhance image authentication and tamper proofing of the encrypted image. In addition, deoxyribonucleic acid-based complementary addition rule is integrated to make the proposed scheme robust against statistical attacks, which also provides immense parallelism to generate the final encrypted image. The proposed methodology has been implemented in MATLAB 7.1. The results are compared with the existing methods. To validate the proposed system, image metrics like correlation coefficient, number of pixels change rate, unified average changing intensity, key sensitivity, cropping attacks, and noise have been computed. Copyright (C) 2015 John Wiley & Sons, Ltd.