Encryption Method of Compressed Images with JPEG Compliance by Shuffling Information Both in Spatial and Frequency Domains

Abstract

Efficient compressed image data encryption is crucial issue for privacy protection because most of the images are stored in the standard compressed form. In this paper, we propose a fast and robust JPEG image encryption method. Our approach achieves efficient and robust image encryption by shuffling both spatial information and frequency domain information. Our method performs encryption in a hierarchical manner from global to local part of images. We shuffle the data while keeping the format compliance with JPEG standard because we want to apply our method on encrypting a part of the whole JPEG image. The partial image encryption is required with images having privacy-sensitive data such as the pedestrian faces or the license plates. Our proposed method uses a single 1024 bits encryption key, from which all the information shuffling and masking data are generated and applied for image encryption. The proposed method is secure against any cryptographic attack as well as perceptual information cracking. Besides, ours is faster than any of the standard data encryption method.