DefinePK

Abstract

The common methodology in data embedding is that in the sender side, the data is to be hidden within the pixel values of the cover image that is producing the stego image. In the receiver side the embedded data in the stego image is retrieved by reversing the same process that is employed for embedding. The data that is to be hidden which is embedded in the AES encrypted image using Reversible Data Hiding (RDH) method. The RDH improves the data hiding process. In existing the data retrieval process the error is accrue it affect the data, in our proposed improve the data hiding and retrieval accuracy. A content owner encrypts the original image using an encryption key and reserves the room for data hiding. Then, a data-hider hides the data in reserve space of the image. If a receiver has the data-hiding key, he can extract the additional data though he does not know the image content. AES algorithm uses two different keys for encryption and decryption. Each byte of the state is combined with a block of the round key using bitwise XOR. Then each byte is replaced with another according to a lookup table. The last three rows of the state are shifted cyclically a certain number of steps. Four bytes in each column were combined. In the receiver side the same procedures are reversed in order to obtain the secret message and the cover image. The performance of the process is measured with the help of the calculation of the Compression Ratio, PSNR and MSE. The measured performance indicates that the proposed system is capable of hiding the messages with better accuracy and the process is reversible also and hence has numerous applications.