A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> PURPOSE: To determine whether digital signature technology (DST) can authenticate digital medical images to the same level of authenticity required for interbank electronic transfer of funds. MATERIALS AND METHODS: Message digests were computed for two magnetic resonance images that differed only by the value of a single bit. RSA (Rivest, Shamir, and Adleman) public key cryptography was used to encrypt each message digest to form a digital signature for each image, a process analogous to the established use of RSA DST for electronic funds transfer. The process was then reversed to authenticate the original image from its digital signature. RESULTS: Although the images differed by less than 0.000095%, their message digests differed at 94% of their characters. The digital signature of the original image proved that it was authentic and that the altered image was not authentic. CONCLUSION: RSA DST can establish the authenticity of images to at least the level of confidence required for interbank electronic t... <s> BIB001 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> To provide an effective authentication method for distribution of medical images, we propose a new fragile watermarking method utilizing segmentation information of medical image contents. For medical image modalities like CT, MRI and PET, tissue structures contain a significant amount of clinical information. Hence, it is important to provide an authenticity check of the segmented blocks. The proposed method is based on cryptographically secure fragile watermarking but eliminates the problem of the block-wise independency of existing methods. The vector quantization (VQ) counterfeiting attack is a known vulnerability due to the block-wise independency of existing methods. In our approach, multiple signatures from two different types of blocks are used to defy such attacks. More secure distribution of medical images can be achieved by embedding the watermark. <s> BIB002 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> This paper proposes a new method to embed data in binary images, including scanned text, figures, and signatures. The method manipulates "flippable" pixels to enforce specific block-based relationship in order to embed a significant amount of data without causing noticeable artifacts. Shuffling is applied before embedding to equalize the uneven embedding capacity from region to region. The hidden data can be extracted without using the original image, and can also be accurately extracted after high quality printing and scanning with the help of a few registration marks. The proposed data embedding method can be used to detect unauthorized use of a digitized signature, and annotate or authenticate binary documents. The paper also presents analysis and discussions on robustness and security issues. <s> BIB003 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> This paper presents a recoverable image tamper proofing technique using the symmetric key cryptosystem and vector quantization for detecting and restoring of a tampered medical image. Our scheme applies the one-way hashing function and the symmetric key cryptosystem to the host image to generate the verification data. To recover the tampered places, the host image is compressed by vector quantization to generate the recovery data. Once an intruder has modified the host image, our scheme can detect and recover the tampered places according to the embedded verification data and the recovery data. Besides, the proposed scheme can withstand the counterfeit attack. <s> BIB004 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical images are stored in PACS (picture archiving and communication systems) that are accessed over the intranet by radiologists for diagnosis. These days the trend is shifting towards a Web based interface for accessing PACS (image) data. This calls for thorough security measures in the information system of the hospital to ensure integrity of medical image data that is being transferred over the public network. The paper analyses various watermarking techniques with a perspective of applying them to medical images stored on the PACS. It discusses the applicability of invertible watermarking technique for ensuring integrity of medical images. Any modification to the watermarked DICOM (digital imaging and communications in medicine) image can be detected with high reliability using invertible fragile watermarking system. A unique content based digital signature can be generated from the image data (pixel data) which would be embedded inside the image in an imperceptible way without increasing the data size that need to be transferred. This signature can be extracted at the radiologist viewer work stations and used for the authentication while the modified pixel data is restored back to original if the image is found to be authentic. This kind of distortion free (erasable) embedding procedure would ensure image retrieval without any modification to pixel data after the authentication process that caters to the unique need of medical images for diagnosis <s> BIB005 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Recently, the medical image has been digitized by the development of computer science and digitization of the medical devices. There are needs for database service of the medical image and long term storage because of the construction of PACS (Picture Archiving and Communication System) following DICOM (Digital Imaging Communications in Medicine) standards, telemedicine, and et al. Furthermore, authentication and copyright protection are required to protect the illegal distortion and reproduction of the medical information data. In this paper, we propose digital watermarking technique for medical image that prevents illegal forgery that can be caused after transmitting medical image data remotely. A wrong diagnosis may be occurred if the watermark is embedded into the whole area of image. Therefore, we embed the watermark into some area of medical image, except the decision area that makes a diagnosis so called region of interest (ROI) area in our paper, to increase invisibility. The watermark is the value of bit-plane in wavelet transform of the decision area for certification method of integrity verification. The experimental results show that the watermark embedded by the proposed algorithm can survive successfully in image processing operations such as JPEG lossy compression. <s> BIB006 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> This paper addresses the secure storage and transmission of medical informatics in rapidly growing applications such as teleradiology and telesurgery. In particular, we propose a frequency domain digital watermarking technique that can be used to authenticate medical images in a distributed diagnosis and home healthcare environment. The most significant result of our method is the semi-reversibility property that undoes most of the degradation attributable to the watermarking process <s> BIB007 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Watermarking in medical images is a new area of research and some works in this area have been reported world wide recently. Most of the works are on the tamper detection of the images and embedding of the Electronics Patient Record (EPR) data in the medical images. Watermarked medical images can be used for transmission, storage or telediagnosis. Tamper detection watermarks are useful to locate the regions in the image where some manipulations have been made. EPR data hiding in images improves the confidentiality of the patient data, saves memory storage space and reduce the bandwidth requirement for transmission of images. This paper discusses various aspects of medical image watermarking and makes a review of various watermarking algorithms originally proposed for medical images. <s> BIB008 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> The number of medical images produced in cardiology and radiology department etc. is rising strongly. New challenges arise in efficient medical data management issues, such as information retrieval and security. A novel method of combining watermarking annotation with independent content feature (ICF) for medical image retrieval is proposed. ICF is extracted by independent component analysis (ICA) to represent medical images, and the digital watermark carrying patient' information text is imperceptibly embedded. Experimental results show that the scheme employs locally salient information from medical image, and it has good retrieval performance, and watermarking algorithm used in the scheme has robustness property to the JPEG compression. <s> BIB009 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Digital medical images are very easy to be modified for illegal purposes. For example, microcalcification in mammography is an important diagnostic clue, and it can be wiped off intentionally for insurance purposes or added intentionally into a normal mammography. In this paper, we proposed two methods to tamper detection and recovery for a medical image. A 1024 × 1024 x-ray mammogram was chosen to test the ability of tamper detection and recovery. At first, a medical image is divided into several blocks. For each block, an adaptive robust digital watermarking method combined with the modulo operation is used to hide both the authentication message and the recovery information. In the first method, each block is embedded with the authentication message and the recovery information of other blocks. Because the recovered block is too small and excessively compressed, the concept of region of interest (ROI) is introduced into the second method. If there are no tampered blocks, the original image can be obtained with only the stego image. When the ROI, such as microcalcification in mammography, is tampered with, an approximate image will be obtained from other blocks. From the experimental results, the proposed near-lossless method is proven to effectively detect a tampered medical image and recover the original ROI image. In this study, an adaptive robust digital watermarking method combined with the operation of modulo 256 was chosen to achieve information hiding and image authentication. With the proposal method, any random changes on the stego image will be detected in high probability. <s> BIB010 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> With the advances in telemedicine, watermarking for Electronic Patient Record(EPR) data hiding has gained profound importance. Most of the techniques proposed for EPR data hiding are not com- pression tolerant. In this paper we propose a new lossless scheme wherein the watermark- ing is done during the JPEG2000 compression process so that both the watermark and the cover image can be recovered as such at the receiving side. The recovered image is the same as that of the decompressed image when no watermarking has been done. Keywords- JPEG2000, EPR, watermark- ing, bit-plane <s> BIB011 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> The development of effective image authentication techniques is of remarkably growing interest. Some recently developed fragile, semi-fragile/robust or hybrid-watermarking algorithms not only verify the authenticity of the watermarked image but also provide self reconstruction capabilities. However, several algorithms have been reported as vulnerable to various attacks, especially blind pattern matching attacks, with insufficient security. We propose a new blind dual-domain self-embedding watermarking scheme with more secure embedding processes of the image's blocks fragile signatures and robust approximations and more reliable local alterations detection with auto-correction capabilities, surviving normal image content preserving operations. Hence it prevents falsification, the real threat to authentication. <s> BIB012 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical image data hiding has strict constrains such as high imperceptibility, high capacity and high robustness. Achieving these three requirements simultaneously is difficult. Though some works are reported in the literature on data hiding, watermarking and steganography which are suitable for telemedicine applications, none performs better in all aspects. Electronic Patient Report (EPR) data hiding for telemedicine demands a blind and reversible method. This paper proposes a novel approach to blind reversible data hiding based on integer wavelet transform. Experimental results shows that this scheme outperforms the prior arts in terms of zero BER (Bit Error Rate), higher PSNR (Peak Signal to Noise Ratio), and large EPR data embedding capacity with WPSNR (Weighted Peak Signal to Noise Ratio) around 53 dB, compared with the existing reversible data hiding schemes. <s> BIB013 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> In this paper, we propose a system which aims at verifying integrity of medical images. It not only detects and localizes alterations, but also seeks into the details of the image modification to understand what occurred. For that latter purpose, we developed an image signature which allows our system to approximate modifications by a simple model, a door function of similar dimensions. This signature is partly based on a linear combination of the DCT coefficients of pixel blocks. Protection data is attached to the image by watermarking. Whence, image integrity verification is conducted by comparing this embedded data to the recomputed one from the observed image. Experimental results with malicious image modification illustrate the overall performances of our system. <s> BIB014 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> In this paper, we consider some basic concepts behind the design of existing robust perceptual hashing techniques for content identification. We show the limits of robust hashing from the communication perspectives as well as propose an approach that is able to overcome these shortcomings in certain setups. The consideration is based on both achievable rate and probability of error. We use the fact that most robust hashing algorithms are based on dimensionality reduction using random projections and quantization. Therefore, we demonstrate the corresponding achievable rate and probability of error based on random projections and compare with the results for the direct domain. The effect of dimensionality reduction is studied and the corresponding approximations are provided based on the Johnson-Lindenstrauss lemma. Side-information assisted robust perceptual hashing is proposed as a solution to the above shortcomings. <s> BIB015 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical image is usually comprised of region of interest (ROI) and region of non interest (RONI). ROI is the region that contains the important information from diagnosis point of view so it must be stored without any distortion. We have proposed a digital watermarking technique which avoids the distortion of image in ROI by embedding the watermark information in RONI. The watermark is comprised of patient information, hospital logo and message authentication code, computed using hash function. Earlier BCH encryption of watermark is performed to ensure inaccessibility of embedded data to the adversaries. <s> BIB016 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Secure authentication of digital medical image content provides great value to the e-Health community and medical insurance industries. Fragile Watermarking has been proposed to provide the mechanism to authenticate digital medical image securely. Transform Domain based Watermarking are typically slower than spatial domain watermarking owing to the overhead in calculation of coefficients. In this paper, we propose a new Discrete Pascal Transform based watermarking technique. Preliminary experiment result shows authentication capability. Possible improvements on the proposed scheme are also presented before conclusions. <s> BIB017 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical Image data require strict security, confidentiality and integrity when transmitted from one hospital to another hospital. This can be achieved by adopting the procedures which can guarantee the image quality as well as secrecy of patient data to unauthorized users. To achieve these requirements we have proposed a multiple watermarking method. The scheme embeds robust watermark in region of non interest (RONI) for achieving security and confidentiality. While integrity control is achieved by inserting fragile watermark in region of interest ROI. Since ROI in the medical image is important from diagnosis point of view so it must be preserved. In order to avoid the distortion caused in ROI due to watermark insertion process, original ROI data is first separated and embedded outside the ROI. This will help in recovery of original ROI at the receiving end in contrast to the techniques reported in the literature which do not guarantee the integrity of the ROI after watermarking process. The image visual quality as well as tamper localization has been evaluated. We have used weighted peak signal to noise ratio (WPSNR) for measuring image quality after watermarking. <s> BIB018 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Nowadays, the transmission of digitized medical information has become very convenient due to the generality of Internet. Internet has created the biggest benefit to achieve the transmission of patient information efficiently. However, it is easier that the hackers can grab or duplicate the digitized information on the Internet. This will cause the following problems of medical security and copyright protection. In order to fulfil the security and convenience issues of the patients following goals like the prevention of medical fault, the real-time detection of abnormal event, the support of clinical decision and developing of medical service based on patient has to be achieved. For this purpose this paper proposes the technique called binary embedding technique. It uses the binary information of the text embedded with semi reversible properties in the image are called binary embedding. This technique prevents the distortion of embedded information in the original image due to addition of noise. The concept of semi reversible property is used retains the original information, image quality before and after the process of watermarking is presented as a statistical analysis <s> BIB019 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> The database systems use the mechanisms of granting and revoking privileges and of authorization control to ensure the security of data. However, some users such as administrators or persons in charge of security have access to comprehensive content of database including patient's information that are of intimate nature and must be discreet. To enhance the security and avoid illegal access of such users, we propose in this article a mechanism using the content-based watermarking technique. Patient's information are encrypted and inserted in an image associated to it. This image, with faculties of object-relational and object-oriented databases, is directly integrated into the database. To check the integrity of the image we use the edge map and invariant moments. <s> BIB020 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Teleradiology applications and universal availability of patient records using web-based technology are rapidly gaining importance. Consequently, digital medical image security has become an important issue when images and their pertinent patient information are transmitted across public networks, such as the Internet. Health mandates such as the Health Insurance Portability and Accountability Act require healthcare providers to adhere to security measures in order to protect sensitive patient information. This paper presents a fully reversible, dual-layer watermarking scheme with tamper detection capability for medical images. The scheme utilizes concepts of public-key cryptography and reversible data-hiding technique. The scheme was tested using medical images in DICOM format. The results show that the scheme is able to ensure image authenticity and integrity, and to locate tampered regions in the images. <s> BIB021 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> This paper proposes a method to authenticate and protect medical images, especially in the region of interest (ROI). The ROI of a medical image is an important area during diagnosis and must not be distorted during transmission and storage in the hospital information system. The rest of the ROI is used for embedding a watermark that contains the patients data and authentication information, and the authentication information is generated from the ROI by analyzing wavelet coefficients with singular value decomposition (SVD), before embedding the watermark into the discrete wavelet transform (DWT) sub-band. It is important that the ratio of ROI and non-ROI areas is consistent between different systems and doctors, and this ratio is analyzed in this paper. The ROI of watermarked medical image is fragile to any distortion, and patients data and authentication information can be easily extracted from non-ROI. The effectiveness of the new approach is demonstrated empirically. <s> BIB022 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> This research paper discussed the usage of watermarking in medical images to ensure the authenticity and integrity of the image and reviewed some watermarking schemes that had been developed. A design of a reversible tamper detection and recovery watermarking scheme was then proposed. The watermarking scheme uses a 640x480x8 bits ultrasound grayscale image as a sample. The concept of ROI (Region Of Interest) and RONI (Region Of Non Interest) were applied. Watermark embedded can be used to detect tampering and recovery of the image can be done. The watermark is also reversible. <s> BIB023 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> In this paper we propose a medical image integrity verification system that not only allows detecting and localizing one alteration, but also provides an approximation of this latter. For that purpose, we suggest the embedding of an image signature or digest derived from Geometric moments of image pixel blocks. Image integrity verification is then conducted by comparing this embedded signature to the recomputed one. This signature helps to approximate modifications by determining the parameters of the nearest generalized 2D Gaussian. Experimental results with local image modification illustrate the overall performances of our method. <s> BIB024 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical image data require strict security, confidentiality and integrity. To achieve these stringent requirements, we propose a hybrid watermarking method which embeds a robust watermark in the region of non-interest (RONI) for achieving security and confidentiality, while integrity control is achieved by inserting a fragile watermark into the region of the interest (ROI). First the information to be modified in ROI is separated and is inserted into RONI, which later is used in recovery of the original ROI. Secondly, to avoid the underflow and overflow, a location map is generated for embedding the watermark block-wise by leaving the suspected blocks. This avoids the preprocessing step of histogram modification. The image visual quality, as well as tamper localization, is evaluated. We use weighted peak signal to noise ratio for measuring image quality of watermarked images. Experimental results show that the proposed method outperforms the existing hybrid watermarking techniques. <s> BIB025 </s> A Review of Medical Image Watermarking Requirements for Teleradiology <s> Objectives and Applications of Watermarking for Medical Images <s> Medical applications such as telediagnosis require information exchange over insecure networks. Therefore, protection of the integrity and confidentiality of the medical images is an important issue. Another issue is to store electronic patient record (EPR) in the medical image by steganographic or watermarking techniques. Studies reported in the literature deal with some of these issues but not all of them are satisfied in a single method. A medical image is distributed among a number of clinicians in telediagnosis and each one of them has all the information about the patient's medical condition. However, disclosing all the information about an important patient's medical condition to each of the clinicians is a security issue. This paper proposes a (k, n) secret sharing scheme which shares medical images among a health team of n clinicians such that at least k of them must gather to reveal the medical image to diagnose. Shamir's secret sharing scheme is used to address all of these security issues in one method. The proposed method can store longer EPR strings along with better authenticity and confidentiality properties while satisfying all the requirements as shown in the results. <s> BIB026
Popularity of Internet has become a boon to patients and low-capital hospitals to utilize the facility to communicate with the clinicians for clinical diagnosis purposes BIB008 , where the security of medical images can presumably be BIB021  Yes, for storing precomputed perceptual hashes BIB015 No No File-format independent Yes ---a Image and audio data can be used, if they are represented as plaintext message addressed to a considerable extent by inserting a properly selected additional data into medical images through digital watermarking. A digital medical image application is therefore one of the prospective target areas of using digital watermarking. Studies show that various watermarking schemes can be used in teleradiology for (1) origin/content authentication BIB025 BIB016 BIB017 BIB018 BIB001 BIB019 BIB005 BIB022 BIB002  BIB007 , (2) EPR annotation BIB026  BIB012 BIB009 BIB013 BIB003 , and (3) tamper detection and recovery of medical images BIB021 BIB023 BIB010 BIB024 BIB004 . Some important aspects of medical image watermarking schemes for their different objectives are summarized below. Origin/Content Authentication Watermarking has received much interest in the research for origin authentication of the medical images. The important details can be stored in images imperceptibly, causing no harm to the ROI of the images. This kind of brief descriptions can be hidden in images immediately after the production of the images in the radiology departments. This can be done by incorporating the watermarking in the different modality machines namely, CT or MRI scanners. The database systems use the mechanisms of granting and revoking privileges and of authorization control to ensure the security of data with the permanent association of the watermark. Our observation suggests the following requirements for this type of watermarking in teleradiology: (1) The watermark should be invisible, blind, and robust; (2) watermark should incorporate the minimum information required for the origin authentication; (3) embedding process must consider the RONI; and (4) proper validation of a watermarking scheme such that the permanent association of the watermark is reliable and safe for diagnosis. Regarding the validation of a watermarking scheme, although it is required for any scheme to be applied in any application scenario, extra care needs to be taken when the effect of watermark embedding is not recoverable. Hence, the permanent association of such robust watermarking requires compromising few bits, which further warrants determining the acceptable range of distortion. Moreover, this type of watermarking should incorporate the RONI embedding for the reliable clinical uses of medical images, particularly, when used along with a reversible watermarking (to form multiple/sequential/hierarchical watermarking scheme) that assumes a secure environment as mentioned in previous section. EPR Annotation EPR and other useful medical information annotation are other key objectives for medical image watermarking. Navas et al. BIB011 suggested three key requirements for EPR data hiding and transmission: BIB006 The recovery of the EPR should be blind due to the unavailability of the original image; (2) zero bit-error rate (BER) is essential for EPR data; and (3) imperceptibility should not be compromised for any reason. These requirements suggest necessary criteria of a watermarking scheme for medical images to be invisible, blind, and reversible. Such a watermarking scheme can be either robust or semi-fragile. For higher capacity, the watermarking scheme can be semifragile, although it requires defining appropriately the set of necessary operations/processing, to which the scheme needs to be robust or not to be. A bit-error correction technique can be used for attaining zero BER and improving watermarking performance   . For additional confidentiality, encryption of the EPR can also be used in watermark generation  BIB020 . Tamper Detection and Recovery (Integrity Control) Medical images in different radiological modalities such as Xrays, ultrasounds, and MRI contain vital medical information that can be tampered with easily available image processing tools. Thus, their protection and authentication seems of great importance, and this need will rise along with the future standardization of exchange of data between hospitals, or between patients and doctors  . Integrity of a medical image can be achieved in three levels BIB014 : (1) tamper detection, (2) tamper localization, and (3) possible recovery by approximating the tampered region. In order to achieve this along with the requirements of medical image needs a watermark to be (1) fragile and blind and (2) reversible or RONI-embedding-based. Hence, fragile watermarking help locate the tampered region with its fundamental property that a watermark becomes invalid for any malicious or unintentional modifications in the watermarked image. If the origin authentication of a medical image is achieved by the robust watermarking, fragile reversible watermarking (in the form of multiple watermarking) can further locate and possibly recover any tampered region of the watermarked image. This will allow the system to control the integrity as well as authentication. In that case, if the watermarking is RONI-based instead of reversible, then the limit of additional distortion must be taken care of. Furthermore, as in EPR annotative watermarking, LSB-embeddingbased watermarking schemes for tamper detection and recovery received much interest in the research, since consideration on the embedding capacity is equally important for the both watermarking objectives.