Symmetric Key Cryptography on Images in AES Algorithm and Hiding Data Losslessly

Reversible (lossless) data embedding (hiding) has drawn lots of interest recently. Being reversible, the original cover content can be completely restored. This paper proposes a novel reversible data hiding scheme with a lower computational complexity and can be used in applications where both the image and the hidden information is highly confidential. It consists of three phases –AES image encryption, data embedding and data extraction/image-recovery phases. Here, the encrypted image is made highly secured by using an AES (Advanced Encryption standard) stream cipher. Although a datahider does not know the original image content, he can embed additional data into the encrypted image using the data hiding key. A receiver may firstly decrypt the encrypted image using the encryption key. This decrypted image is similar to the original image. With the datahiding key, the embedded data can be correctly extracted while the original image can be perfectly recovered.