Reversible data hiding in image encryption with efficient compression and enhanced security

In Recent years, more and more attention is paid to Reversible Data Hiding (RDH) in encrypted images, since it maintains the excellent property that the original cover can be lossless recovered after embedded data is extracted while protecting the image content´s confidentiality. All previous methods embed data by reversibly vacating room from the encrypted images, which may be subject to some errors on data extraction and/or image restoration. This work proposes a novel method by reserving room before encryption with a traditional RDH, and thus it is easy for the data hider to reversibly embed data in the encrypted image. Image compression is also achieved through this method. The proposed method can achieve real reversibility, where the data extraction and image recovery are free of any error. This method can embed more than 10 times as large payloads for the same image quality as the previous methods, such as for Peak Signal to Noise Ratio.