Medical Image Authentication Research Articles

Image watermarking algorithm based on DCT and Arnold transform

According to the safety of the medical image in medical information system, the robust watermarking method is put forward, and it is suitable for medical image authentication and protection. Firstly, the visual feature vectors of medical image are obtained through DCT transformation, which is used to make watermark's embedding and extraction. Then, chaotic encryption technique is used in watermark to improve the security of watermark information. Lastly, the zero watermarking concepts are combined to get the watermark with the qualities against conventional watermark attacks and geometric attacks. The experimental results show that the method can effectively extract the watermark information, and has good invisibility and robustness. In addition, compared with the existing watermarking technology, this method can not only reduce the complexity of the watermark embedding, but can improve the capacity of watermark embedding and it has better flexibility and practicability.

A blind medical image watermarking: DWT-SVD based robust and secure approach for telemedicine applications

In this paper, a blind image watermarking scheme based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. In this scheme, DWT is applied on ROI (region of interest) of the medical image to get different frequency subbands of its wavelet decomposition. On the low frequency subband LL of the ROI, block-SVD is applied to get different singular matrices. A pair of elements with similar values is identified from the left singular value matrix of these selected blocks. The values of these pairs are modified using certain threshold to embed a bit of watermark content. Appropriate threshold is chosen to achieve the imperceptibility and robustness of medical image and watermark contents respectively. For authentication and identification of original medical image, one watermark image (logo) and other text watermark have been used. The watermark image provides authentication whereas the text data represents electronic patient record (EPR) for identification. At receiving end, blind recovery of both watermark contents is performed by a similar comparison scheme used during the embedding process. The proposed algorithm is applied on various groups of medical images like X-ray, CT scan and mammography. This scheme offers better visibility of watermarked image and recovery of watermark content due to DWT-SVD combination. Moreover, use of Hamming error correcting code (ECC) on EPR text bits reduces the BER and thus provides better recovery of EPR. The performance of proposed algorithm with EPR data coding by Hamming code is compared with the BCH error correcting code and it is found that later one perform better. A result analysis shows that imperceptibility of watermarked image is better as PSNR is above 43 dB and WPSNR is above 52 dB for all set of images. In addition, robustness of the scheme is better than existing scheme for similar set of medical images in terms of normalized correlation coefficient (NCC) and bit-error-rate (BER). An analysis is also carried out to verify the performance of the proposed scheme for different size of watermark contents (image and EPR data). It is observed from analysis that the proposed scheme is also appropriate for watermarking of color image. Using proposed scheme, watermark contents are extracted successfully under various noise attacks like JPEG compression, filtering, Gaussian noise, Salt and pepper noise, cropping, filtering and rotation. Performance comparison of proposed scheme with existing schemes shows proposed scheme has better robustness against different types of attacks. Moreover, the proposed scheme is also robust under set of benchmark attacks known as checkmark attacks.

Region-based hybrid medical image watermarking for secure telemedicine applications

In this paper we propose a novel region based hybrid medical image watermarking (MIW) scheme to ensure authenticity, integrity and confidentiality of medical images. In this scheme a digital medical image is partitioned into region of interest (ROI) and the region of non interest (RONI). To detect and localize ROI tampering with high accuracy pixel wise positional and relational bits are calculated. Positional bit is calculated with respect to MSBs, row and column of the pixel. Relational bit shows the relation between MSBs. Two original LSBs of each ROI pixel are replace by their corresponding positional and relational bits. Original LSBs of ROI pixels are concatenated and embedded in RONI for ROI recovery in the case of tampering. Multiple watermarks i.e. electronic patient record (EPR), hospitals logo and LSBs of ROI are embedded simultaneously as a robust watermark in RONI using IWT-SVD hybrid transform. The proposed scheme is blind and free from false positive detection. Various experiments have been carried out on different medical imaging modalities to evaluate the performance of the proposed scheme in terms of imperceptibility, robustness, tamper detection, localization, recovery and computation time. ROI tampering is detected and recovered with high accuracy. Thus, the proposed scheme is effective in telemedicine applications.

A robust medical image watermarking against salt and pepper noise for brain MRI images

The ever-growing numbers of medical digital images and the need to share them among specialists and hospitals for better and more accurate diagnosis require that patients' privacy be protected. During the transmission of medical images between hospitals or specialists through the network, the main priority is to protect a patient's documents against any act of tampering by unauthorised individuals. Because of this, there is a need for medical image authentication scheme to enable proper diagnosis on patient. In addition, medical images are also susceptible to salt and pepper impulse noise through the transmission in communication channels. This noise may also be intentionally used by the invaders to corrupt the embedded watermarks inside the medical images. A common drawback of existing watermarking methods is their weakness against salt and pepper noise. The research carried out in this work addresses the issue of designing a new watermarking method that can withstand high density of salt and pepper noise for brain MRI images. For this purpose, combination of a spatial domain watermarking method, channel coding and noise filtering schemes are used. The region of non-interest (RONI) of MRI images from five different databases are used as embedding area and electronic patient record (EPR) is considered as embedded data. The quality of watermarked image is evaluated using Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM), and the accuracy of the extracted watermark is assessed in terms of Bit Error Rate (BER).

Numbering with spiral pattern to prove authenticity and integrity in medical images

With the rapid development of technology in digital multimedia, manipulation and misconduct of digital data are soaring. The watermarking procedure is seen as helpful to protect the security of digital images which are highly confidential such as medical images. In this study, an efficient watermarking method for greyscale images is proposed. The scheme is designed to achieve good numbering pattern, exact detection and image recovery. The proposed scheme uses a unique spiral pattern numbering before implementing the block-based mechanism for embedding. The experiment tests the difference between using normal pattern and unique spiral pattern in numbering, and the results show that the proposed method produces a great quality value of embedded image with great tamper localization and recovery ability. This function can help in proving authenticity and integrity of medical images in the system.

Secured medical image watermarking with DNA codec

Modern healthcare systems are based on managing diagnostic information of patients through E-health. E-health refers to the Internet enabled healthcare applications involving transacting personal health records or information and other internet based services including e-Pharmacy where security threats is a major concern . This paper introduces a hybrid watermarking and encryption technique for copyright protection and authentication of medical images. The medical image is watermarked in wavelet domain where in the Electronic Health Record (EHR) is used as watermark and hospital logo as the reference image. Embedding of the EHR data is based on energy band selection and in reference to the bit location in the reference image A Composite algorithm for improved image security is proposed by taking the advantages of DNA based image encryption and genetic algorithms (GA). A number of deoxyribonucleic acid (DNA) masks are created using logistic map function and DNA conversion rules. Then encryption is performed on the watermarked image to generate a number of cipher images. Genetic algorithm (GA) is applied to find the best DNA mask in iterative manner until the condition is met. The experimental results demonstrate the capability of the proposed scheme to the available security attributes in both frequency and encryption domain while minimizing image distortion and also resists to various attacks.

Medical image authentication using SLT and IWT schemes

Over the years, different watermarking techniques have been used for medical image authentication purposes. Some techniques have been presented to detect tampering in the medical image while others can also recover the tampered region after the tamper detection. Many of the previous medical image authentication schemes have successfully achieved their aims; however, the robustness of the authentication scheme against unintentional attacks has not been highlighted sufficiently. This paper presents a new medical image authentication scheme in which the medical image is divided into two regions (i.e., region of interest (ROI) and region of non-interest (RONI)). Then two watermarking methods based on Slantlet transform (SLT) are used to embed data in the ROI and the RONI. The proposed scheme can be used for tamper detection, localization, and recovery in addition to the data hiding. To generate the recovery information of the ROI, a new method has been proposed based on the integer wavelet transform (IWT) coefficients. The experiments that have been conducted to evaluate the proposed authentication scheme proved that it is efficient not only in achieving its main tasks that have been mentioned above but also in having robustness against unintentional attacks (i.e., JPEG compression, additive Gaussian noise (AGN), and salt-and-pepper noise) and that makes it more suitable for the practical applications.

Large-Capacity Reversible Watermarking Algorithm for Medical Image Based on Block Histogram of Difference

This paper proposes a high-capacity reversible watermarking algorithm for medical image analysis based on the difference block histogram, which will benefit the medical image authentication and doctor–patient confidentiality. By dividing the original medical image into blocks, the method displaces the peak point of a block's histogram of difference and embeds multi-bit information at 1 pixel point. In so doing, secret communication and storage of large-capacity invisible medical diagnoses and patients personal confidential data can be achieved. Once the watermark is extracted, not only the image integrity is authenticated, but also the original image and personal data of the patient can be recovered in a nondestructive way. With low computational complexity, a high embedding capacity and little demand for auxiliary information, the proposed algorithm is highly secure and practical.

High Capacity, Reversible Data Hiding Using CDCSAlong with Medical Image Authentication

High Capacity, Reversible Data Hiding Using CDCSAlong with Medical Image Authentication

Inversion attack resilient zero‐watermarking scheme for medical image authentication

Medical images are watermarked with patient data to enforce patient authentication and identification in radiology practices. In addition to common threats such as signal processing and geometric attacks, medical image watermarking systems are susceptible to a new class of threats called ‘inversion attack’, leading to ambiguities in establishing rightful ownership. This study presents an ‘inversion attack’ resilient zero-watermarking system, in the hybrid Contourlet transform – singular value decomposition domain for medical image authentication. This scheme preserves the fidelity of the host image without introducing any artefacts and employs triangular number generating function and Hu's image invariants to confront ‘inversion attacks’. The performance of the system is evaluated with medical images of different modalities and a quick response code watermark that contains patient data. The experimental results demonstrate the robustness of the system against ‘ambiguity attacks’ and signify its appropriateness for secured medical image exchange between remote radiologists.

A novel tamper detection-recovery and watermarking system for medical image authentication and EPR hiding.

Recently, the literature has witnessed an increasing interest in the study of medical image watermarking and recovery techniques. In this article, a novel image tamper localization and recovery technique for medical image authentication is proposed. The sparse coding of the Electronic Patient Record (EPR) and the reshaped region of Interest (ROI) is embedded in the transform domain of the Region of Non-Interest (RONI). The first part of the sparse coded watermark is use for saving the patient information along with the image, whereas the second part is used for authentication purpose. When the watermarked image is tampered during transmission between hospitals and medical clinics, the embedded sparse coded ROI can be extracted to recover the tampered image. The experimental results demonstrate the efficiency of the proposed technique in term of tamper correction capability, robustness to attacks, and imperceptibility.

A Robust Medical Image Authentication Technique using QR Code and DWT

Image authentication plays a vital role in safeguarding the originality as well as helps to retain the integrity of the data. It is also used as proof in case of content delivery. This paper proposes an efficient and effective medical image authentication technique by embedding information of a patient and doctor through corresponding QR codes in selected DWT sub-band of that image. At the receiver end QR codes are extracted and information containing in the QR codes are retrieved using Smart Phone or through standard QR Code Reader. General Terms Image Authentication, QR Code, Smart Phone

Authentication and Recovery of Medical Diagnostic Image Using Dual Reversible Digital Watermarking

This paper proposes a new region-based tampering detection and recovering method that utilizes both reversible digital watermarking and quad-tree decomposition for medical diagnostic image's authentication. Firstly, the quad-tree decomposition is used to divide the original image into blocks with high homogeneity, and then we computer pixels' linear interpolation as each block's recovery feature. Secondly, these recovery features as the first layer watermarking information is embedded by using simple invertible integer transformation. In order to enhance the proposed method's security, the logistic chaotic map is exploited to choose each block's reference pixel. The second layer watermark comprises by the quad-tree information and essential parameters for extraction are embedded by LSB replacement. In the authentication phase, the embedded watermark is extracted and the source image is recovered, and the similar linear interpolation technique is utilized to get each block's feature. Therefore, the tampering detection and localization can be achieved through comparing the extracted feature with the recomputed one, and the extracted feature can be used to recover those tampered regions with high similarity to their original state. Experimental results show that, compared with previous similar existing scheme, the proposed method not only achieves high embedding capacity and good visual quality of marked and restored image, but also has more accuracy for tampering detection.

Fragile and blind watermarking technique based on Weber's law for medical image authentication

In developing countries such as India, transmission of medical images over the network is essential for providing health services to rural/remote population. During this transmission, a small distortion in the medical image may lead to wrong conclusions. Thus, arises the need to embed some authentication information in medical images to authenticate transmitted image. In this study, a blind and fragile watermarking technique based on Weber's law is proposed. Here, fragile watermark is inserted by quantising intensity of selected pixels in a medical image. As the proposed technique is fragile, it detects even a small change made to watermarked image and locates blocks where distortion has been made. Besides being able to detect all malicious changes that affect the quality of watermarked image, it is tolerant to image compression, which is essential to transmit images over the network. The proposed technique is highly imperceptible as the watermark is inserted by modifying intensity of dark pixels selected using Weber's law. An extension of the proposed technique is also given to enhance its capacity. Experimental results on standard medical image database prove the efficacy of the proposed method over existing works.

A QR Code Based Zero-Watermarking Scheme for Authentication of Medical Images in Teleradiology Cloud

Healthcare institutions adapt cloud based archiving of medical images and patient records to share them efficiently. Controlled access to these records and authentication of images must be enforced to mitigate fraudulent activities and medical errors. This paper presents a zero-watermarking scheme implemented in the composite Contourlet Transform (CT)—Singular Value Decomposition (SVD) domain for unambiguous authentication of medical images. Further, a framework is proposed for accessing patient records based on the watermarking scheme. The patient identification details and a link to patient data encoded into a Quick Response (QR) code serves as the watermark. In the proposed scheme, the medical image is not subjected to degradations due to watermarking. Patient authentication and authorized access to patient data are realized on combining a Secret Share with the Master Share constructed from invariant features of the medical image. The Hu's invariant image moments are exploited in creating the Master Share. The proposed system is evaluated with Checkmark software and is found to be robust to both geometric and non geometric attacks.

Authentication of DICOM medical images using independent component analysis (ICA)

This paper proposes a blind content-based watermarking scheme for image authentication using ICA and DCT. The watermark to be embedded is obtained from the host image itself in terms of the Frobenius norm of the mixing matrix obtained during ICA. These are embedded in the mid-frequency DCT coefficients. The proposed method correctly authenticates the image even under normal image processing operations and it correctly detects tampering and identifies the tampered regions of the image. The average PSNR value in this proposed ICA-based technique is around 97 which makes it superior than the existing watermarking techniques.

Protecting patient privacy from unauthorized release of medical images using a bio-inspired wavelet-based watermarking approach

This paper identifies a novel digital watermarking approach for copyright protection and authentication of medical images based on the wavelet transformation. We consider the problem of protecting [email protected]? medical records and tracing illegally distributed medical images in a group communication environment. We employ the particle swarm algorithm and genetic algorithm optimization principles to obtain performance improvement in our work. In the proposed method, the strength of the embedded watermark and noise are controlled to prevent the images from being used directly regarding to visual properties of the host signal. These parameters and also the places of the embedded watermarks are varied to find the most suitable ones for images with different characteristics. The experimental results show that the proposed algorithm yields a watermark which is invisible to human eyes, robust against a wide variety of common attacks and reliable enough for tracing colluders.

Wavelet Packets-Based Blind Watermarking for Medical Image Management

The last decade has witnessed an explosive use of medical images and Electronics Patient Record (EPR) in the healthcare sector for facilitating the sharing of patient information and exchange between networked hospitals and healthcare centers. To guarantee the security, authenticity and management of medical images and information through storage and distribution, the watermarking techniques are growing to protect the medical healthcare information. This paper presents a technique for embedding the EPR information in the medical image to save storage space and transmission overheads and to guarantee security of the shared data. In this paper a new method for protecting the patient information in which the information is embedded as a watermark in the discrete wavelet packet transform (DWPT) of the medical image using the hospital logo as a reference image. The patient information is coded by an error correcting code (ECC), BCH code, to enhance the robustness of the proposed method. The scheme is blind so that the EPR can be extracted from the medical image without the need of the original image. Therefore, this proposed technique is useful in telemedicine applications. Performance of the proposed method was tested using four modalities of medical images; MRA, MRI, Radiological, and CT. Experimental results showed no visible difference between the watermarked and the original image. Moreover, the proposed watermarking method is robust against a wide range of attacks such as JPEG coding, Gaussian noise addition, histogram equalization, gamma correction, contrast adjustment, and sharpen filter and rotation.

Medical Images Authentication through Repetitive Index Modulation Based Watermarking

In this work we propose a Repetitive Index Modulation (RIM) based digital watermarking scheme for authentication and integrity verification of medical images. Exploiting the fact that many types of medical images have significant background areas and medically meaningful Regions Of Interest (ROI), which represent the actual contents of the images, the scheme uses the contents of the ROI to create a content-dependent watermark and embeds the watermark in the background areas. Therefore when any pixel of the ROI is attacked, the watermark embedded in the background areas will be different from the watermark calculated according to the attacked contents, thus raising alarm that the image in question is inauthentic. Because the creation of the watermark is content-dependent and the watermark is only embedded in the background areas, the proposed scheme can actually protect the content/ROI without distorting it.

Using Statistical Texture Analysis for Medical Image Tamper Proofing

This article discusses an approach for both authentication of medical images and confidentiality for the related textual data in an online medical application paradigm. The image authentication is achieved in a soft manner through a feature-based digital signature while the confidentiality of the related patient information is achieved through reversible data hiding. The selected features are robust towards geometric transformations, while fragile towards texture alterations that are characteristic of medical images. The processing scheme is done in a block by block basis to permit the localization of tampered image’s regions. The effectiveness of the scheme, proven through experiments on a sample of medical images, enables us to argue that implementing mechanisms lying on this approach will help to maintain personal patient privacy and medical image integrity.