scholarly journals A New Reversible Date-Hiding Algorithm for Encrypted Images

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Laicheng Cao ◽  
Hao Zhou

In order to effectively increase embedding capacity and completely extract the watermarking information in information hiding of encrypted images, a new reversible watermarking embedding algorithm based on rhombus prediction model and difference histogram shifting ideas is proposed. Firstly, the images are pretreated according to rhombus prediction model. Then, the watermarking information is embedded in encrypted images by effective combination of homomorphism encryption scheme and reversible watermarking techniques. Finally, the watermarking information is completely extracted and the images are recovered based on computed difference histogram from left to right and from top to bottom. So, the efficiency and reversibility are ensured when watermarking information is embedded in encrypted image. Experiment results show that the proposed algorithm is simple and easy to realize, the embedding capacity is effectively increased, watermarking information is completely reversible, and the image can be recovered with no distortion.

2021 ◽  
Vol 15 (2) ◽  
pp. 1-28
Author(s):  
Manisha Duevedi ◽  
Sunil Kumar Muttoo

Reversible data hiding in encrypted images (RDH-EI) has attracted various communities that deal with security. Xiao et al. presented RDH-EI that uses pixel value ordering (PVO) and additive homomorphism for encryption ensuring that the embedding capacity of plain and encrypted image remains relatively same. However, the size of location map required to manage over/under flow blocks increased drastically reducing the overall embedding capacity. In the paper, a new PVO-based separable RDH scheme is proposed using double encryption. The original image is encrypted using chaotic mapping in Phase 1, ensuring that the performance of PVO algorithm in an encrypted domain is similar to that in plain domain. Secret data is embedded in this encrypted image. The embedded image is re-encrypted using additive homomorphism to enhance security. The proposed scheme is more efficient as it improves the pure embedding rate and total embedding capacity of the image by reducing location map size, overcoming the drawback of Xiao et al.


2020 ◽  
Vol 14 ◽  
Author(s):  
Ram Ratan ◽  
Arvind Yadav

Aim: The aim of the paper is to analyse the security strength of image encryption schemes which are based on pixel rotation and inversion functions. The key independent image decryption methodologies are presented to obtain original images with intelligible contents from encrypted images using neighbourhood similarity characteristics and divide-and-conquer attack. Background: The efficiency and security strength of secure communication of sensitive data depends on the computing resources and cryptographic strength of encryption schemes. An encryption scheme is cryptographically strong if it does not leave any weakness, vulnerability or pattern which could be exploited by cryptanalyst to obtain original image from an encrypted image. Prior to use of any image encryption scheme for multimedia security applications, it should be analysed for its security strength to ensure the safety of information so that an adversary could not extract intelligible information from encrypted image data. A number of encryption schemes developed for image security applications and claimed highly secure but some of these are cryptanalyzed and found insecure. Objective: The analysis of image ciphers which encrypt plain images by transforming its pixels using circular rotation or inversion function in a random fashion is carried out to decrypt encrypted images to obtain original images. The encryption schemes, namely ‘Chaotic Image Encryption (CIE)’ and ‘Graphical Image Encryption (GIE)’, were reported secure but we find that these schemes are insecure and meaningful information can be obtained. We exploit image similarity characteristics to mount cryptanalytic attacks to obtain original images without any knowledge of the encryption/decryption keys. These encryption schemes encrypting the specified region-of-interest (ROI) are also analysed to decrypt ROI encrypted images. Method: The methodology of decryption is key independent and based on divide-and-conquer strategy to obtain original images from given encrypted images. It utilizes the neighbourhood similarity of pixels in an image which is measured in terms of pixel-to-pixel difference between adjacent pixels for pixel inversion based image cipher (GIE) and line-to-line correlation between adjacent lines for pixel rotation based image cipher (CIE). The ROI encrypted and masked encrypted images are also decrypted. Results: Experimental test results show that the decrypted images obtained are quite intelligible and one can understand the contents of decrypted images. It is also seen that an image cipher encrypting the ROI can be decrypted by utilizing unencrypted region surrounding encrypted ROI part of an image. Conclusion: It has been shown that CIE, GIE, ROI and masked encryption schemes reported for image security applications are insecure and not providing adequate security. Such encrypted images can be decrypted without key knowledge successfully with quite intelligibility by considering image similarity characteristics of neighbouring pixels and applying divide-and-conquer attack strategy. Future work: The presented key independent decryption methodology can be considered to cryptanalyze the encryption schemes under noise attack scenario as future work to see the applicability of decryption methods with respect to increase the noise in encrypted images. Moreover, other modern encryption schemes based on pixel inversion and rotation functions can be analysed for their security strength.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhaohui Li ◽  
Yiqing Wang ◽  
Zhi Wang ◽  
Zheli Liu ◽  
Jian Zhang ◽  
...  

This paper proposes a scheme of reversible data hiding in encrypted images based on multikey encryption. There are only two parties that are involved in this framework, including the content owner and the recipient. The content owner encrypts the original image with a key set which is composed by a selection method according to the additional message. Thus, the image can be encrypted and embedded at the same time. Additional message can be extracted given that the recipient side could perform decryption strategy by exploiting spatial correlation; then, original image can be recovered without any loss. Compare with other current information hiding mechanism, the proposed approach provides higher embedding capacity and is also able to perfectly reconstruct the original image as well as the embedded message. Rate distortion of the proposed method outperforms the previously published ones.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xi-Yan Li ◽  
Xia-Bing Zhou ◽  
Qing-Lei Zhou ◽  
Shi-Jing Han ◽  
Zheng Liu

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.


2019 ◽  
Vol 1 ◽  
pp. 223-237
Author(s):  
Terlumun Gbaden

The widespread use of images in various sectors of life makes its protection increasingly necessary and important. An improvement over encryption and decryption algorithm using exponential logistic chaotic map was proposed. In this work, we adopt an encryption/decryption strategy for colour images using the exponential logistic chaotic map. The proposed encryption/decryption algorithms are implemented in MATLAB for computer simulation. The experimental results indicate that the proposed algorithms can be used successfully to encrypt/decrypt images with secret keys. The performance analysis using histogram uniformity analysis and correlation coefficient show that the algorithms give larger space, quick speed and easy to realize. The encrypted images have good encryption effect and low correlation coefficient rendering it a good candidate for confidential and secure means of transmitting image information in untrusted networks.


Author(s):  
Faten H. MohammedSediq Al-Kadei

<p><span>Encryption and hiding images are becoming a hot research area and a broad prospect for application. This article uses a secure algorithm with Low Significant Bit method to hide an encrypted high-resolution color bitmap image in two selectively color images (i.e., two cover images). The paper introduces a two-level hiding encrypted image using MATLAB-GUI programming language. In the beginning, with a key image using XOR bit operation, the original RGB image is encrypted. After that, the encrypted image is hidden into the first cover image. The cover image is then hidden into another cover to make the secret image safer without changing the perceptual quality for both covers. Then, the algorithm is tested on many bitmap images, which can be an important image, fingerprint image, samples of secret medicine, or bank account pattern. The correlation histograms demonstrate a high correlation for all encrypted images. The PSNR is used to find steganography quality for the two cover images after hiding the secret image showing a high quality for the two levels of hiding operation</span></p>


Cryptography ◽  
2020 ◽  
pp. 480-497
Author(s):  
Lin Gao ◽  
Tiegang Gao ◽  
Jie Zhao

This paper proposed a reversible medical image watermarking scheme using Redundant Discrete Wavelet Transform (RDWT) and sub-sample. To meet the highly demand of the perceptional quality, the proposed scheme embedding the watermark by modifying the RDWT coefficients. The sub-sample scheme is introduced to the proposed scheme for the enhancement of the embedding capacity. Moreover, to meet the need of security, a PWLCM based image encryption algorithm is introduced for encrypting the image after the watermark embedding. The experimental results suggests that the proposed scheme not only meet the highly demand of the perceptional quality, but also have better embedding capacity than former DWT based scheme. Also the encryption scheme could protect the image contents efficiently.


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