Reversible Data Hiding in Homomorphic Encrypted Domain by Monitoring Ciphertext Group

Since few years, a new problem is trying to combine in a single step, compression, encryption and data hiding. So far, few solutions have been proposed to combine image encryption and compression for example. Nowadays, a new challenge consists to embed data in encrypted images. Since the entropy of encrypted image is maximal, the embedding step, considered like noise, is not possible by using standard data hiding algorithms. A new idea is to apply reversible data hiding algorithms on encrypted images by wishing to remove the embedded data before the image decryption. Recent reversible data hiding methods have been proposed with high capacity, but these methods are not applicable on encrypted images. In this paper we propose an analysis of the local standard deviation of the marked encrypted images in order to remove the embedded data during the decryption step. We have applied our method on various images, and we show and analyze the obtained results.

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High-Capacity Reversible Data Hiding in Encrypted Images by Information Preprocessing

Complexity ◽

10.1155/2020/6989452 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Xi-Yan Li ◽

Xia-Bing Zhou ◽

Qing-Lei Zhou ◽

Shi-Jing Han ◽

Zheng Liu

Keyword(s):

Data Hiding ◽

Reversible Data Hiding ◽

High Capacity ◽

Main Idea ◽

Original Image ◽

Chaos Encryption ◽

Secret Information ◽

Encrypted Image ◽

Encrypted Images ◽

Scanned Documents

With the development of cloud computing, high-capacity reversible data hiding in an encrypted image (RDHEI) has attracted increasing attention. The main idea of RDHEI is that an image owner encrypts a cover image, and then a data hider embeds secret information in the encrypted image. With the information hiding key, a receiver can extract the embedded data from the hidden image; with the encryption key, the receiver reconstructs the original image. In this paper, we can embed data in the form of random bits or scanned documents. The proposed method takes full advantage of the spatial correlation in the original images to vacate the room for embedding information before image encryption. By jointly using Sudoku and Arnold chaos encryption, the encrypted images retain the vacated room. Before the data hiding phase, the secret information is preprocessed by a halftone, quadtree, and S-BOX transformation. The experimental results prove that the proposed method not only realizes high-capacity reversible data hiding in encrypted images but also reconstructs the original image completely.

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High-Capacity Reversible Data Hiding in Encrypted Images Based on Adaptive Predictor and Compression of Prediction Errors

Mathematics ◽

10.3390/math9172166 ◽

2021 ◽

Vol 9 (17) ◽

pp. 2166

Author(s):

Bin Huang ◽

Chun Wan ◽

Kaimeng Chen

Keyword(s):

Image Encryption ◽

Data Hiding ◽

Reversible Data Hiding ◽

High Capacity ◽

Huffman Coding ◽

Prediction Errors ◽

Original Image ◽

Embedding Capacity ◽

Secret Data ◽

Encrypted Images

Reversible data hiding in encrypted images (RDHEI) is a technology which embeds secret data into encrypted images in a reversible way. In this paper, we proposed a novel high-capacity RDHEI method which is based on the compression of prediction errors. Before image encryption, an adaptive linear regression predictor is trained from the original image. Then, the predictor is used to obtain the prediction errors of the pixels in the original image, and the prediction errors are compressed by Huffman coding. The compressed prediction errors are used to vacate additional room with no loss. After image encryption, the vacated room is reserved for data embedding. The receiver can extract the secret data and recover the image with no errors. Compared with existing approaches, the proposed method efficiently improves the embedding capacity.

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