Separable Reversible Data Hiding in an Encrypted Image

Since times immemorial, security of data to maintain its confidentiality, proper access control, integrity and availability has been a major issue in data communication. Today images and data transfer in mobile phone communication, e-commerce, Pay-TV, sending private e-mails, transmitting financial information and touches on many aspects of daily lives. We wanted to develop a scheme in which the data embedded in an image and the image itself would be secured from any unauthorized access. This scheme would also be a merit in military and medical services. This paper proposed a scheme for separable reversible data hiding technique in an encrypted image. The original image was encrypted using an encryption key. Then, a data-hider hides the data using the data-hiding key. With an encrypted image containing additional data, if a receiver has the data-hiding key, it can extract the additional data though it does not know the image content and if it has the encryption key, it 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 key it can extract the additional data and recover the original content without any error by exploiting. This results in the security of data and image privacy.