Chaos based crossover and mutation for securing DICOM image

This paper proposes a novel encryption scheme based on combining multiple chaotic maps to ensure the safe transmission of medical images. The proposed scheme uses three chaotic maps namely logistic, tent and sine maps. To achieve an efficient encryption, the proposed chao-cryptic system employs a bio-inspired crossover and mutation units to confuse and diffuse the Digital Imaging and Communications in Medicine (DICOM) image pixels. The crossover unit extensively permutes the image pixels row-wise and column-wise based on the chaotic key streams generated from the Combined Logistic-Tent (CLT) system. Prior to mutation, the pixels of the crossed over image are decomposed into two images with reduced bit depth. The decomposed images are then mutated by XOR operation with quantized chaotic sequences from Combined Logistic-Sine (CLS) system. In order to validate the sternness of the proposed algorithm, the developed chao-cryptic scheme is subjected to various security analyses such as statistical, differential, key space, key sensitivity, intentional cropping attack and chosen plaintext attack analyses. The experimental results prove the proposed DICOM cryptosystem has achieved a desirable amount of protection for real time medical image security applications.