This paper proposes a novel scheme of separable multiple bits reversible data hiding in encrypted domain based on LWE (Learning with Errors). Multi-band data could be embedded by recoding the redundancy of ciphertext, which does enhance the capacity of embedding data. With embedded ciphertext, the additional data can be extracted by using data-hiding key, and the original data can be recovered losslessly by using decryption key, the processes of extraction and decryption are separable. By deducing the error probability of the scheme, parameters in the scheme which directly related to the scheme’s correctness is mainly discussed, and reasonable ranges of the parameters are obtained by experiments. When analyzing the security, the probability distribution function of the embedded cipher text is deduced and the statistic features of ciphertext are analyzed, which both proved the embedded data isn’t detective. The proposed scheme is based on encryption process, so it can apply to different kinds of media vehicle. Experimental results have demonstrated that the proposed scheme can not only achieve statistical security without degrading the quality of encryption, but realize that 1bit original data can maximally load multiple-bit additional data in encrypted domain.

Separable Multiple Bits Reversible Data Hiding in Encrypted Domain

This paper proposes an improved version of Shiu’s encrypted image-based reversible data hiding with public key cryptography (EIRDH-P) The original work vacates embedding room by difference expansion technique and embeds one bit into each pair of adjacent encrypted pixels The data extraction and image recovery can be achieved by comparing all pairs of decrypted pixels Shius’ work did not fully exploit the correlation inherent in the neighborhood of a pixel and required side information to record the location map These two issues could reduce the amount of differences and in turn lessen the potential embedding capacity This letter adopts a better scheme for vacating room before public key encryption using prediction-error expansion method, in which the pixel predictor is utilized by interpolation technique The experimental results reveal that the proposed method offers better performance over Shiu’s work and existing EIRDH-P schemes For example, when the peak signal-to-noise ratio of the decrypted Lena image method is 35, the payload of proposed method is 074 bpp, which is significantly higher than 05 bpp of Shius’s work

Encrypted Image-Based Reversible Data Hiding with Public Key Cryptography from Interpolation-Error Expansion.

A novel reversible data hiding algorithm for encrypted image based on interpolation error expansion is proposed. The proposed method is an improved version of Shiu' s. His work does not make full use of the correlation of the neighbor pixels and some additional side information is needed. The proposed method adopts the interpolation prediction method to fully exploit the pixel correlation and employ the Paillier public key encryption method. The algorithm is reversible. In the proposed method, less side information is demanded. The experiment has verified the feasibility and effectiveness of the proposed method, and the better embedding performance can be obtained, compared with some existing RDHEI-P methods. Specifically, the final embedding capacity can be up to 0.74 bpp (bit per pixel), while the peak signal-to-noise ratio (PSNR) for the marked image Lena is 35 dB. This is significantly higher than Shiu's method which is about 0.5 bpp.

Reversible Data Hiding for Encrypted Image Based on Interpolation Error Expansion

This paper proposes a novel reversible data hiding algorithm with image contrast enhancement based on homomorphic public key cryptosystem. The additional data is embedded based on histogram shifting after preprocessing procedure. Then the image is encrypted using public key and side information is embedded. On the receiver side, the image with contrast enhancement is obtained directly after image decryption using private key. Due to the correlation between adjacent pixels, date extraction and image recovery can be implemented. To our best knowledge, it is the first reversible data hiding in encrypted image algorithm with image contrast enhancement. Experimental results have demonstrated the feasibility and effectiveness of the proposed method.

Reversible Image Data Hiding with Homomorphic Encryption and Contrast Enhancement

Unique LSB Compression Data Hiding Method

It is very crucial to design efficient methods to provide authentication to document images mainly for images whose security must be protected. In digital media the authentication, tampering detection and repairing of the tampered data is main concern. Nowadays many digital documents are transferred on the internet regularly e.g. circuit diagrams, scanned cheques, signed documents, drawings, design drafts etc. Here the method of image authentication, tampering detection and repairing is explained. The grayscale image document image authentication with self repair method is provided. The authentication signal is calculated from binary image of the original document image. Secret sharing scheme is used to calculate this authentication signal. The extra alpha channel is embedded in the original grayscale document image. The calculated authentication signal is then embedded in this alpha channel. This is one of the way of visual cryptography in which image is visible but authentication signal will not be recognized. Then this authentic image is encrypted for better security. this whole procedure is done at sender side. In second module i.e. receiver side the image is decrypted. Then the embedded authentication signal is extracted from the received authentic image. The new authentication signal is calculated from the binary image of the received authentic image. This new authentication signal is compared with the extracted signal and the integrity check is provided. If data modification is detected, then the method is proved to repair the tampered pixels using the reverse secret sharing method. The tampering of data is detected successfully in this method without any original image backup. This type of secret sharing scheme is helpful for reducing the risk of incidental partial data loss. This method is also applicable to the color image. Algorithm for color image is also same as grayscale images. In this paper the result is provided only for the grayscale images and supposed to expand for color images as well.

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Ashwini Jarali

Papers

Unique LSB Compression Data Hiding Method

Image Tampering Detection and Repairing