Separable data hiding in encrypted image based on compressive sensing

A novel scheme for separable data hiding in an encrypted image based on compressive sensing (CS) is presented. In the first phase, the content owner encrypts the original image with an encryption key and leaves some space for the data-hider to embed data. Therefore the image is enlarged. The data-hider embeds additional data to the image for a specific purpose in a fixed location. As the image is enlarged, the data-hider can compress the image to the original size using CS with the data-hiding key. Thus, the encrypted image with embedded data is generated. The way to obtain image content and additional data is separable. If a receiver has the encryption key, he can decrypt the unintelligent data to obtain an image similar to the original one, but cannot extract the additional data. Similarly, if a receiver has the data-hiding key, he can extract the watermark without seeing the content of the image. If the receiver has both the encryption key and the data-hiding key, he can extract the additional data and recover the original image by exploiting CS recovery algorithms.