Research Article Robust and Fragile Medical Image Watermarking: A Joint Venture of Coding and Chaos Theories Atta Ur Rahman , 1 Kiran Sultan, 2 Dhiaa Musleh, 1 Nahier Aldhafferi , 3 Abdullah Alqahtani, 3 and Maqsood Mahmud 4 1 Department of Computer Science, College of Computer Science and Information Technology, Imam Abdulrahman Bin Faisal University (IAU), P.O. Box. 1982, Dammam, Saudi Arabia 2 Department of CIT, JCC, King Abdulaziz University, Jeddah, Saudi Arabia 3 Department of Computer Information System, College of Computer Science and Information Technology, Imam Abdulrahman Bin Faisal University (IAU), P.O. Box. 1982, Dammam, Saudi Arabia 4 Department of MIS, College of Business Administration, Imam Abdulrahman Bin Faisal University (IAU), P.O. Box 1982, Dammam, Saudi Arabia Correspondence should be addressed to Atta Ur Rahman; dr.ataurahman@gmail.com Received 24 October 2017; Revised 23 March 2018; Accepted 16 April 2018; Published 2 July 2018 Academic Editor: Maurizio Schmid Copyright © 2018 Atta Ur Rahman et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A secure spatial domain, hybrid watermarking technique for obtaining watermark (authentication information) robustness and fragility of the host medical image (content integrity) using product codes, chaos theory, and residue number system (RNS) is proposed. e proposed scheme is highly fragile and unrecoverable in terms of the host image, but it is significantly robust and recoverable in terms of the watermark. Altering the medical image may result in misdiagnosis, hence the watermark that may contain patient information and organization logo must be protected against certain attacks. e host medical image is separated into two parts, namely, the region of interest (ROI) and region of noninterest (RONI) using a rectangular region. e RONI part is used to embed the watermark information. Moreover, two watermarks are used: one to achieve authenticity of image and the other to achieve the robustness against both incidental and malicious attacks. Effectiveness in terms of security, robustness, and fragility of the proposed scheme is demonstrated by the simulations and comparison with the other state-of-the-art techniques. 1. Introduction Digital watermarking is one of the most promising techniques for authentication, copyright protection, and ownership identification. In digital watermarking, the watermark in- formation could be fragile, semifragile, robust, or hybrid. Fragile watermarks are very sensitive and are used for tamper detection, while the robust watermarks are used to withstand common image processing operations. e watermark having robustness against friendly attacks while fragile against mali- cious attacks is called semifragile, and the one having mixed properties is called a hybrid watermark [1]. Medical image watermarking is becoming more promising in terms of se- curity, privacy, and authenticity; hence, several schemes have been investigated in this regard. Major purposes of the medical image watermarking are authenticity and integrity control. Here, the authenticity is referred to as the measure through which it is ensured that the image source is valid and the image belongs to the right patient. e integrity control is a capability to validate that image has not been tampered by any means. Since, in some cases, little modifications in the medical image may cause a wrong diagnosis [2, 3], the authors in [4] focused on integrity control and authentication of patient electronic record (PER). While in [5], the authors focused on three areas in medical image watermarking that are authentication, data hiding, and their combination. In this paper, a DICOM image was selected for experiments, after being divided into ROI and RONI parts. e major drawback of the technique was fragility of the watermark. Because the PER is an important information, it must not be preserved through the fragile Hindawi Journal of Healthcare Engineering Volume 2018, Article ID 8137436, 11 pages https://doi.org/10.1155/2018/8137436