Secure and Authenticated Reversible Data Hiding in Encrypted Image

This work proposes a Secure and authenticated discrete reversible data hiding in cipher images deals with security and authentication. In the first phase, a content owner encrypts the original uncompressed image using an encryption key. Then, a data hider may compress the least significant bits of the encrypted image using a data hiding key to create a sparse space to accommodate some additional data. With an encrypted image containing additional data, if a receiver has the data hiding key, receiver can extract the additional data though receiver does not know the image content. If the receiver has the encryption key, can decrypt the received data to obtain an image similar to the original one, but cannot extract the additional data. If the receiver has both the data hiding key and the encryption key, can extract the additional data and recover the original content without any error by exploiting the spatial correlation in natural image when the amount of additional data is not too large. It is also a drawback because if the receiver has any one key as known, and then he can take any one information from the encrypted data. In order to achieve authentication SHA-1 algorithm is being used.