Improved Approach to Encrypt Medical Data

Abstract

Abstract. In this paper, an improved steganography technique has been proposed based on embedding in middle pixels of a 3*3 window in which corner pixels are used to detect edges in an image so that only those can be chosen which has varying intensity i.e. edges in them. In the initial step the ROI object is detected. To select the ROI, rectangular box is used on which the salient object is located by applying active contour segmentation. Two matrices are made from sanitized area pixels each containing LSB and MSB bits. Pseudo random no generation algorithm is used for MSB bits encryption. Non overlapping square blocks are used to convert the whole image and edge block are calculated by taking four corner pixels of a 3*3 block. To embed the encrypted MSB bits into block one bit LSB steganography is used. ROI object is blacked out after embedding stego image. The reverse of embedding process is extraction. By taking edge blocks encrypted MSB bits are extracted from the stego image during extraction to the extracted bits decryption algorithm is applied and in the original location the resulted image bits are stored. Experimental results show that there is 20% increase in embedding capacity from the existed system and system is able to hide only useful information of a medical image. As MSB bits are chosen for embedding, system has even higher embedding capacity in which remaining LSB bits can be useful for data hidden