Data hiding with thumbnail-preserving encryption for cloud medical images

To serve a convenient healthcare network, storing medical images and diagnosis records in the cloud is a straightforward solution. Encrypting the medical images before uploading them to the cloud is a trivial strategy to prevent data breaches. However, the availability of images is also reduced. Since all images look noisy, one cannot obtain the intended image by a quick viewing of the file folder. In this paper, we propose a total solution to these considerations. A reversible data hiding scheme based on thumbnail-preserving image encryption is presented. By leveraging a multi-scale Haar wavelet transform and extended run-length coding, we can produce thumbnail-preserving encrypted medical images that provide a sufficient vacating room for embedding electronic patient records. The experimental results demonstrate that our scheme effectively balances the confidentiality and availability of encrypted medical images. It provides over 1 bit per pixel of capacity for embedding electronic patient records, making it suitable for cloud-based medical data management.