Enhancing Security and Authentication in Medical Image through ROI based Watermarking Scheme

The medical images and its data are transferred securely over the public network. The medical image watermarking method is used for enhancing security and authentication of medical data. This paper uses SHA 256, AES (Advanced Encryption Standard) and arithmetic coding techniques. Original medical image is separated into ROI and RONI. The ROI of medical image is irregularly shaped and it is an area which contains important information. Advanced Encryption Standard algorithm encrypt the patient information with help of secret key and SHA 256 algorithm is applied to ROI to calculate hash value. This hash value and secret information are embedded into least significant bits of the ROI image and compressed by arithmetic coding technique. Hash value of the original image will be compared with the hash value of extracted watermarked image for authentication.