Robust Zero-watermarking Algorithm for Medical Images Based on ORB and DCT.

With the rapid development of the Internet technology field, the use of the Internet to transmit medical images has gradually become an efficient and convenient transmission method. It improves the efficiency of medical services, which allows medical institutions and doctors to share medical images and diagnostic information quickly. However, there are also some potential security risks in the transmission of medical images on the Internet, and data leakage and data tampering occur frequently. This paper proposes a zero-watermarking algorithm for medical images based on Oriented FAST and Rotated BRIEF (ORB) and Discrete Cosine Transform (DCT) to solve the above problems. Firstly, this algorithm is used to extract the feature vector of the medical image, and then the feature sequence of the medical image is obtained by combining the perceptual hashing algorithm, and the logistic map is used to perform chaotic scrambling encryption on the watermark image. Finally, the zero-watermarking technology is used to embed and extract the watermark. The experimental results show that the algorithm can effectively extract and restore the watermark under conventional attacks and geometric attacks and can effectively protect the information security of medical images, and the algorithm has good robustness and invisibility, which has a particular development prospect in the field of medical images.