Reversible Data Hiding In Encrypted JPEG Images

As cloud storage becomes more common,many business and individuals prefer backing up their digital images in the public cloud for easy access,convenient sharing or cost savings,which led to increasing concerns about the privacy and security of the images.An image is usually encrypted by turning into incomprehensible before stored in the public cloud for the purpose of protecting the privacy and security.Reversible data hiding technique in encrypted domain can be employed to embed additional data,such as labels,authentication messages and timestamps,within the encrypted images for ease of management.Since JPEG image,which is the default image format of network transmission and many digital devices,is common in the Internet,research on reversible data hiding for encrypted JPEG bitstreams has been of great value.In this paper,based on the observations and summaries of the weaknesses existing in the state-of-the-art related works,a novel reversible data hiding scheme for encrypted JPEG bitstreams,which can overcome those weaknesses,is proposed.First,a bitstreams-based JPEG image encryption is employed to encrypt plaintext JPEG images.In the cloud,additional data,such as labels,authentication messages and timestamps,are directly embedded into the encrypted JPEG images with our proposed data hiding technique,which based on invariant zero-run length.From the marked encrypted JPEG images,the extraction of hidden data and the decryption of the original images can be done independently.Extensive experimental results show the effectiveness and advancement of the proposed scheme.Moreover,it can be seen from the experiments that the proposed scheme is separable,achieve much higher embedding capacity,preserve file sizes of the marked encrypted JPEG images and has better format compatibility and low computational complexity compared to those of the related schemes.