Research On Encrypted Medical Image Robust Retrieval Algorithm

With the popularization of medical imaging technology,medical images for clinical,teaching and research have shown an explosive growth trend.In order to achieve effective organization and management,but also to facilitate doctors to exchange and share resources to solve the problem of uneven distribution of medical resources,storing a wide variety of medical images on cloud servers will be the development trend of medical information systems.Medical images often contain the patient's private information.Storing private information in a partially trusted third party undoubtedly increases the possibility of leaking patient's privacy.In order to protect the privacy of the patient from being leaked and the data is not tampered with during transmission,it is often necessary to encrypt the medical image before uploading the image to the cloud server.Most current image retrieval schemes do not support cipher-text operations.Therefore,if a medical image needs to be retrieved,it needs to be decrypted before it can be performed.This will increase the risk of information leakage and damage the security of the image.Therefore,it is of great significance to study the robust retrieval of encrypted medicalimages.In view of the above situation,this paper mainly carried out the following research:1)First,the development of the current image retrieval technology and image encryption technology are described.The problem that the content-based image retrieval technology can not achieve the robust retrieval of medical images in the ciphertext domain is analyzed.2)Research medical image encryption algorithms based on DFT,DWT-DCT and DWT-DFT.The algorithm mainly utilizes the robustness of image frequency domain space and the key space security of high dimensional chaotic sequence to ensure the security and reliability of the algorithm.Through experiments,the above encryption and decryption algorithms are verified and analyzed.3)Study the method of perceptual hash extraction for frequency-domain encrypted medical images based on DFT,DWT-DCT and DWT-DFT,and research corresponding encryption medical image retrieval algorithms.The robustness of these algorithms is verified through simulation experiments.Comprehensive analysis and comparison of the robustness and rapidity of the above three robust retrieval algorithms for cryptographic medical images yields the scope of application of the algorithm.At the same time,the direction of future research work on encrypted medical image retrieval is indicated.