Confidential storage of medical images - a chaos-based encryption approach

Abstract

The recent developments in telehealth increase the demands of clinical and non-clinical services which lead to work on medical image security to provide better teleradiology services. One of the mandatory characteristics of the image security is confidentiality. The traditional block and stream ciphers are suitable for encrypting small data or the file which is not having redundant information. Hence, this study proposes an encryption algorithm to provide confidentiality to medical images using chaotic maps. The different enhanced chaotic economic maps (ECEM) are derived by substituting sine and cosine functions in basic chaotic economic map (CEM) equation. The ECEMs are studied in detail with respect to their bifurcate nature and Lyapunov exponents to achieve greater robustness in encryption. The improved maps generate different chaotic sequences which are employed in confusing, swapping and diffusing 16-bit DICOM image pixels, thereby assure confidentiality. After scrambling, the different security analyses such as statistical, entropy, differential, key space, key sensitivity, cropping attack, noise attack, decryption efficacy analysis are performed to prove the effectiveness of the proposed algorithm.