A Review of Medical Image Watermarking Requirements for Teleradiology <s> Discussion and Conclusions <s> A number of analogies to cryptographic concepts have been made about watermarking. In this paper, we argue that these analogies are misleading or incorrect, and highlight several analogies to support our argument. We believe that the fundamental role of watermarking is the reliable embedding and detection of information and should therefore be considered a form of communications. We note that the fields of communications and cryptography are quite distinct and while communications systems often combine technologies from the two fields, a layered architecture is applied that requires no knowledge of the layers above. We discuss how this layered approach can be applied to watermarking applications. <s> BIB001 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Discussion and Conclusions <s> There is now an increasing demand for sharing images and image data for process integration among healthcare institutions. Web services technology has recently been widely proposed and gradually adopted as a platform for supporting integrations. The Health Insurance Portability and Accountability Act (HIPAA) imposes rules as national standards to protect individuals' health information in the U.S., highlighting security and privacy protection requirements. There are so far no holistic solutions to tackle the various protection issues in this area, especially in inter-institutional healthcare progress integration. We propose the exchange of medical images through a medical image exchange platform (MIEP), especially replacing ad-hoc and manual exchange practices. We show how contemporary technologies of Web services and watermarking can help archive images with layered implementation architecture. Through dedicated Web services technologies with watermarking mechanism, not only can the development, deployment, and maintenance of software be streamlined, the privacy protection in medical image exchanges as required by disparate processes can also be much facilitated <s> BIB002
Study of security and privacy problems is a continuous process and is mainly influenced by the technological advances in the field. It has been more than a decade since the study of digital watermarking (finding relevance and suitability, and developing of new schemes and their evaluation) has found its way to medical image applications. However, watermarking for medical images is not practically well accepted yet. This reluctance is instigated from the incomplete justification of watermarking applicability for the strict requirements of medical images. In this paper, an extensive investigation is conducted and described in three parts, namely: (1) the security and privacy requirements; (2) conventional security measures and their limitations; and (3) justification of using watermarking for medical images, in teleradiology. The need for sharing of medical images and information is growing rapidly for improved healthcare access, delivery, and standards. Web services technology has recently been widely proposed and gradually adopted as a platform for supporting systems' integration BIB002 . The DICOM standard as well as ISO27799 and other government regulations such as HIPAA, CFR 45, Directive 95/46/EC, etc., impose rules as national/international standards to protect individuals' health information, highlighting security and privacy protection requirements. Our study suggested three mandatory characteristics: confidentiality, reliability, and availability that need to be achieved for medical images in teleradiology. However, a complete solution for various security problems discussed so far is still lacking. Although conventional security measures have their limitations, they cannot be replaced with any individual measure. For example, authentication based on watermarking cannot replace classical cryptographic authentication protocols that protect communication channels [131] . However, well-known cryptographic algorithms can be used to guarantee the privacy, authenticity, and integrity of messages embedded in multimedia content, where there is no cryptographic solution for the threat of unauthorized watermark removal BIB001 . To this, other conventional security measures may still be required, while watermarking complements the security of multimedia data. Especially, watermarking provides a great prospect for teleradiology because it functions as a communication tool with the authenticity of the origin/sender, nonrepudiation, detection of data tampering, memory and bandwidth saving, integrity of the image, and so on. We observed that the general requirement for any medical image watermarking implies that watermarking needs to be invisible and blind, whereas, robustness, reversibility, and RONI embedding as well as other design parameters must be taken into consideration according to the objectives dictated by the application scenario. Although it is not identified as a general requirement, a prior clinical validation of a watermarking scheme may always be subjected to its medical image application irrespective of the type and properties of watermark(s). As a result, any permanent or temporary modification due to watermark embedding may remain reliable and safe for diagnosis. In teleradiology, the primary objective of a watermarking scheme for medical images should be authentication (e.g., origin or content). EPR annotation and integrity control (or, tamper detection and recovery) can be a further goal(s) to form a multiple watermarking scheme. Thereby, a properly designed multiple watermarking scheme may have the potential intelligence to address the rising problem in teleradiology. Although the concept of multiple watermarking scheme is not new, their applicability in teleradiology naturally requires more explicit consideration on the performance evaluations and security analysis, including overall computational complexity, speed, and cost-benefit analysis. Finally, without considering and characterizing, the required design and evaluation parameters systematically may pose serious flaws and may render a watermarking scheme ultimately useless for the application. Therefore, this study recommends a systematic development of multiple watermarking schemes and their complete assessment through defining the parameters properly such that they can offer a better complementary solution for achieving improved security in teleradiology. Hence, a suitable generic watermarking model and a point of reference for benchmarking is recommended as another milestone to be addressed in future research.