Reversible Data Hiding for JPEG Image Based on Paillier Encryption

Abstract

AbstractWith the convenient and rapid development of cloud storage, data privacy violations have become increasingly prominent. Reversible Data Hiding (RDH) can be used to embed additional data in encrypted data stored in the cloud. Most encrypted RDH algorithms are performed in uncompressed images and are not widely employed in popular JPEG images. Therefore, an effective RDH scheme in encrypted JPEG images is proposed in the paper. This algorithm first extracts the distribution characteristics of DCT coefficients, and chaotic encryption is utilized to encrypt the DC coefficients. Then the number of AC coefficients “0” is calculated in each DCT block to generate the embedded sequence in descending order. The paillier encryption and the homomorphic encryption is employed the multiplication feature to embed for the AC coefficient. During the embedding process, the range of the encrypted ciphertexts is determined according to the paillier parameter and the embedding threshold. It ensures that the ciphertexts do not out the range of the DCT coefficient while maintaining a small file increment. The experimental results show that the scheme effectively improves the data embedding capacity and image encryption quality compared to other state-of-the-art encrypted RDH schemed. The scheme also realizes the synchronization of data extraction between the ciphertext image and the original image. The experimental analysis further shows that this scheme has high embedding capacity and good image quality. The scheme can be applied to application scenarios with high embedded capacity and high-security requirements.KeywordsDCT coefficientChaotic encryptionPaillier homomorphic encryptionReversible data hiding