A Region-Based Lossless Watermarking Scheme for Enhancing Security of Medical Data

Abstract

This paper presents a lossless watermarking scheme in the sense that the original image can be exactly recovered from the watermarked one, with the purpose of verifying the integrity and authenticity of medical images. In addition, the scheme has the capability of not introducing any embedding-induced distortion in the region of interest (ROI) of a medical image. Difference expansion of adjacent pixel values is employed to embed several bits. A region of embedding, which is represented by a polygon, is chosen intentionally to prevent introducing embedding distortion in the ROI. Only the vertex information of a polygon is transmitted to the decoder for reconstructing the embedding region, which improves the embedding capacity considerably. The digital signature of the whole image is embedded for verifying the integrity of the image. An identifier presented in electronic patient record (EPR) is embedded for verifying the authenticity by simultaneously processing the watermarked image and the EPR. Combining with fingerprint system, patient's fingerprint information is embedded into several image slices and then extracted for verifying the authenticity.

A Review of Medical Image Watermarking Requirements for Teleradiology

“…Invertibility seldom gets interest for nonblind detector since detection itself requires the original image, although developing a blind detector for invertible watermarking is more challenging, especially when a high embedding capacity is desired. Developing this type of watermarking received much attention in medical image applications to avoid any misdiagnosis from distortions in a watermarked image [8,72,78].…”

“…Watermarking allows using DS or perceptual hashing for appropriate applications [78,105,109,110]. Watermarking systems have room for employing encryption for the additional confidentiality of metadata (e.g., in generating watermark).…”

A Heuristic Automatic and Robust ROI Detection Method for Medical Image Warermarking

“…The other solution is to ignore ROI during the watermarking process by having this part left without embedding any data and by concentrating on embedding data into the region of non interest (RONI) through reversible [14][15][16][17][18][19] or non-reversible methods [20][21][22][23][24][25][26].…”

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.…”