Reversible watermarking for authentication of DICOM images

Abstract

We propose a watermarking scheme that can recover the original image from the watermarked one. The purpose is to verify the integrity and authenticity of DICOM images. We used 800x600x8 bits ultrasound (US) images in our experiment. SHA-256 of the whole image is embedded in the least significant bits of the RONI (Region of Non-Interest). If the image has not been altered, the watermark will be extracted and the original image will be recovered. SHA-256 of the recovered image will be compared with the extracted watermark for authentication.

An Improved Tamper Detection and Localization Scheme for Volumetric DICOM Images

“…The advantages of using watermarking include enabling authentication information such as the metadata to be embedded into the medical images as visually unperceivable watermark payload and providing continuous authenticity and integrity protection of the images beyond the point of internal network. A number of digital watermarking techniques for medical images have been reported [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These watermarking techniques can be broadly categorized into non-reversible [3,4] and reversible watermarking [2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in the literature where reversible watermarking has been more widely implemented.…”

Authentication and Self-Correction in Sequential MRI Slices

“…These future personal e-health platforms, due to the strict ethics and legislative rules concerning medical data, have to ensure confidentiality, reliability (authenticity and integrity check), availability, and safe transfer of the medical files [1][2][3]. Apart from legislation issues, the quality of the biomedical images has to remain intact to ensure a correct diagnosis.…”

“…The rest of the part that does not contain any clinical findings is the region of non-interest (RONI) [1][2][3]. In many works, the watermark is inserted into the RONI, in that way, it leaves the ROI intact without any imperceptible modifications [1][2][3]7].…”

“…Concerning the embedding space, they are categorized into spatial and frequency domain [5]. In the spatial domain, the watermark is inserted by modifying the pixel values or more often the least significant bit [2,3,5]. In the frequency domain, the watermark is embedded in some transformed signal coefficients (frequency bands) [1,8].…”

“…In [1,3,7,11], the ROI is selected manually or automatically as a rectangle. In [10], a simple thresholding method operates in 2×2 pixel blocks to define the ROI with good detail.…”