Study Of Reversible Data Hiding In Encrypted JPEG Image

Encryption and steganography are two important branch of information security. Encryption makes plaintext not visible to unauthorized users, and steganography realizes secure communication by hiding the secret information.Reversible steganography in encrypted domain is a new technique combining encryption with steganography. It has superior performance and plays an important role in the field of multimedia security by realizing reversible data hiding in encrypted multimedia, satisfying some special application scenario like medical image, military, electronic legal document. In this paper, we study how to realize reversible data hiding in encrypted JPEG image.First of all, we introduce the research background and research status of reversible steganography in encrypted image by learning some related theory. Because reversible steganography in encrypted image is closely linked to cryptography and reversible data hiding, this article summarizes some related knowledge about cryptography, reversible data hiding and The combination of encryption and steganography. It also analyze some classical algorithm.Secondly, we study the process of the 2D-CML chaotic image encryption algorithm and JPEG-TO-JPEG reversible steganographic algorithm and analyse the characteristics of two. By improving the latter, we combine the 2D-CML chaotic image encryption algorithm with the improved JPEG-TO-JPEG reversible steganographic algorithm and propose an reversible data hiding scheme in encrypted JPEG image. The scheme generates chaotic sequence and encrypts the DC coefficient and the signs of All AC coefficients in the quantized DCT domain of JPEG image, then dives each 8*8 block into multiple turple and uses zigzag scanning order to determine the position of embedding. So as to achieve the goal of random embedding data. Experiments show that the proposed algorithm has superior performance in guaranteeing the security of the JPEG image and realizing extraction and decryption separately.Finally, by summarizing the proposed algorithm, we point out the next direction of improvement and make prospect of the steganographic technique in encrypted JPEG image.