Sensitive Patient Data Hiding using a ROI Reversible Steganography Scheme for DICOM Images.

The exchange of medical images over the Internet has evoked significant interest over the past few years due to the introduction of web and cloud based medical information systems. The protection of sensitive data has always been a key indicator in the performance of such systems. In this context, this work presents an algorithm developed for Digital Imaging and Communications in Medicine (DICOM) medical images, which applies secret-sharing steganography methods for ensuring the integrity of sensitive patient data as well as the important parts of the image. In the proposed algorithm, images are divided into two parts: the region of interest (ROI) and the region of non interest (RONI). Patient data and integrity hashes are positioned inside the ROI while the information (map) needed to recover the ROI before insertion is positioned in the RONI. Security of the extraction process is assured through the use of cryptography. The experimental results prove that the original (cover) images and the stego images provide an excellent visual equality result in terms of PSNR. Furthermore, they prove that the proposed scheme can be efficiently used as a steganography scheme in DICOM images with limited smooth areas.