Enhanced Lorenz-Chaotic Encryption Method for Partial Medical Image Encryption and Data Hiding in Big Data Healthcare

Image encryption is highly required in the big data healthcare cloud to improve the security of the medical image for remote access. Data hiding method is the process of storing the medical information of the patient in the medical image in the hidden format. Many existing data hiding methods are based on wavelet and chaotic map due to its effectiveness. Wavelet based methods have limitations of lack of phase information, poor directionality, and shift sensitivity. Chaotic map is applied to improve the security of the medical image and chaotic map has the limitation of low sensitive to control parameters and initial conditions. In this research, the Improved Chaos Encryption (ICE) is applied to improve the security based on randomness. The average energy is calculated in the images and compared with adaptive threshold to segment the Lorenz 96 model applied in the chaos encryption algorithm to improve the model security. Lorenz 96 increased the randomness of the chaos encryption method due to its high sensitivity. Medial images were used to test the performance of the ICE in the image encryption and image hiding. The proposed ICE model evaluated the quality of the recovered and decrypted image in the various embedding rate. The result shows that the proposed ICE model has the PSNR value of 104.7 dB compared to the LSB-ROI method which has 97.61 dB PSNR.