Zigzag pixel indicator based secret data hiding method

Histogram-shifting-imitated reversible data hiding

Reversible Data Hiding (RDH) should be secured as per requirements to protect content in open environments such as the cloud and internet. Integrity and undetectability of steganographic images are amongst the main concerns in any RDH scheme. As steganographic encryption using linear prediction over bit-planes is challenging, so the security and embedding capacity of the existing RDH techniques could not be adequate. Therefore, a new steganographic technique is proposed which provides better security, higher embedding capacity and visual quality to the RDH scheme. In this technique, the cover image is divided into n-bit planes (nBPs) and linear prediction is applied to it. Next, the histogram of the residual nBPs image is taken, and secret data bits are encrypted using the RC4 cryptographic algorithm. To embed the encrypted secret data bits, the histogram shifting process is applied. This is achieved by using peak and zero pairs of residual nBPs images. This scheme provides security to the cover image and hidden data. The proposed RDH scheme is capable of extracting the embedded secret data accurately and recovering the original cover or residual nBPs image.

Steganography, the technology of protecting a secret message by embedding it inside a cover image, continues to be investigated and enhanced as an alternative data protection method. This paper deals with hiding multimedia files in true color RGB cover images with an emphasis on reducing the cover size, increasing hiding capacity and enhancing security of the hidden data. A proposed model (DuoHide) is presented in which a secret multimedia file, regardless of its type, is processed without un-compression, and divided between two cover images of equal size and dimensions. The multimedia file is read as a stream of bytes and split vertically into two parts, one part contains the least significant half-bytes, and the other part contains the most significant half-bytes. The two parts are hidden inside two uncompressed RGB cover images using a least significant 4-bit replacement technique. The resulting dual stego images are expected to be sent separately, through different channels, to avoid capture of both stego files by an adversary. Extraction of the secret file is achieved through merging LSB half-bytes from the two stego files. The extracted file is identical in content and structure with the original secret file. The implemented DuoHide system was evaluated using a set of public multimedia files, images, audios, and videos, of various sizes. The secret file sizes ranged from 5% to about 100% of the cover image's size. The experimental results showed that even at the highest embedding ratio, which is based on the secret-to-cover ratio, there were no perceptible visual differences between cover and stego images. The PNSR value was calculated as PSNR1, for cover1 and stego1, and PSNR2 for cover2 and stego2. The lowest PSNR value was around 31 dB for the highest embedding ratio, which is considered acceptable concerning statistical imperceptibility. The PSNR value increased as the embedding ratio decreased, reaching around 65 Decibel (dB) for the case of 5% secret-to-cover ratio. The integrity of the extracted secret file was verified through a bitwise comparison between original and extracted files, which showed zero differences. The DuoHide model is expected to provide better security for the hidden file, in case an attacker manages to capture one of the stego images and recover the hidden content because the attacker will only get an incomprehensible set of half-byte bits. An additional advantage of using a pair of stego files is that of reducing stego file size by 50%, to avoid problems and limitations of transmitting large files, especially that multimedia files are often large, and they cannot be compressed because they are already compressed. Security of the DuoHide system can further be improved by randomizing storage locations within the two stego images.

Traditional image steganography techniques leverage different kinds of data hiding schemes to hide secret data while preserving good image visual quality. The image quality is measured by its PSNR value, which is based on the mean square error between the stego image and the cover image. From the viewpoint of visual experience, the adjustments of gray level values on the high contrast portions and on the smooth portions make completely different effects. A slight change of gray level on the smooth region will be noticed and explained as a noise, while increasing the contrast of an image edge will lead to a more pleasant visual effect. In this paper, we propose a novel method of data hiding. The cover image is divided into small blocks and each block is analyzed to classify into smooth block or high contrast block. For each high contrast block, the secret data are appended in the way that the block contrast is further enhanced. On the other hand, only half amount of secret data are embedded into a smooth block. Experimental results show that our method provides satisfactory results.

This paper presents a novel reversible data hiding method, which can recover the original image content without distortion from the stego images after the secret data have been extracted. The method utilizes the original cover image to finally generate two visually similar stego images by embedding additional data. During the data embedding process, the pixels in the first stego image are utilized to embed secret data by applying the proposed prefix matching technique, which exploits each of the gray values to carry one or two bits only with ± 1 operation. Pixels in the second stego image are adaptively modified to carry rest secret data by referring to the first stego image using the directed LSB embedding. For the recipient, the additional data can be extracted from the two stego images with the DH key, and the original cover image can be recovered with the location map. If the cover image has no boundary gray-values, one can always recover the cover image from the two stego images without the aid of any extra information. Experiments show that the proposed method can achieve desirable embedding capacity and maintain a high level of image quality.

The multi-bit image steganography (Paul et al. Multimedia Tools and Applications 76(5):7445–7471, 2017) proposed by Paul et al. provides high embedding capacity, and adapts the embedding position of messages to image content. This paper investigates the security and robustness of multi-bit steganography. In detection resistant experiment, we embed secret messages into cover images with multi-bit image steganography to get corresponding stego images, and adopt a more popular steganalyzer (SRM) to extract features of cover images and stego images. The ensemble classifier is trained with default settings. The experimental results show detection resistance performance of multi-bit image steganography is poor. In robustness test, we embed secret messages into cover images with multi-bit image steganography to get stego images, and attack the stego images with Stirmark. Then, we extract the secret messages from the attacked stego images. The experimental results demonstrate that we can not recover the secret messages from the attacked stego images. Therefore, there are flaws in detection resistant test and robustness test of multi-bit image steganography.

This paper presents a new secret sharing scheme for identification of cheaters in the elections. In a proposed scheme secret image (voter ID) is embedded into cover image (Indian emblem) of same size and generates n stego images. The resulting stego images are visually good and look like a cover image. Various image quality metrics are used to assess the quality of stego images. Out of n stego images only last two stego images are required to reconstruct the secret and cover images without any loss. The proposed scheme offers high embedding capacity. Experimental results of proposed scheme shown to be superior in terms of PSNR and visual quality than existing schemes.

In this study, the StegoCrypt technique is proposed using a combination of Discrete Wavelet Transform (DWT) and One-Time Pad (OTP). Cover image with size 512 ∗ 512 transformed with Wavelet transformation of four levels. For the first level to the third level, the subband LL is selected to obtain LL3 subband. At fourth level, the LL3 is then transformed into HH4 subband with help of wavelet transformation. This is done to gain strength and imperceptibility to the stego image. The secret message that is used is a binary image with a size of 32 ∗ 32. Secret image is encrypted with OTP before it is inserted in the host image. To test the quality of imperceptibility, stego images were measured using PSNR and MSE. While the quality of secret image reconstruction of extraction and decryption results are measured by using NCC. Robustness of stego image is also tested with JPEG compression attacks. From the test results can be concluded that the proposed method works well and get a better quality stego image. The secret image reconstruction results are also perfect as well as robust to JPEG compression attacks.

Reversible data hiding is a technique that embeds secret data into cover media through an invertible process. In this paper, we propose a reversible data hiding scheme that can embed a large amount of secret data into image with imperceptible modifications. The prediction-error, difference between pixel value and its predicted value, is used to embed a bit '1' or '0' by expanding it additively or leaving it unchanged. Low distortion is guaranteed by limiting pixel change to 1 and averting possible pixel over/underflow; high pure capacity is achieved by adopting effective predictors to greatly exploit pixel correlation and avoiding large overhead like location map. Experimental results demonstrate that the proposed scheme provides competitive performances compared with other state-of-the-art schemes.

Secret sharing (SS) schemes based on cellular automata (CA) are considered as secure encrypting algorithms, where several secret data can be shared among some persons. Recently the SS schemes can be applied to solve real-world problems, such as security in cloud computing. The principal obstacle of use of the SS scheme is its considerably high computational cost; especially if a large amount of secret data must be encrypted and shared. In this work, we propose a parallel CA-based SS scheme suitable for any kinds of digital data in the graphic processing unit using compute unified device architecture technology. The uses of global memory and shared memory are analyzed from computational effectiveness and security points of view. The experimental results show the proposed parallel implementation provides a speedup rate more than 18-fold compared with its sequential implementation. Also we show the increase of the security level of the parallel implementation with respect to the sequential implementation.

Today, the amount of data generated is enormous. Despite the creation and transmission of this data on the internet, the presence of many threats to this data is not at all surprising, but on the contrary, the security of this data is a very important issue. There are always different methods that can be used to somehow secure data against security threats. One such rapidly developing technique is the science of steganography. There are several ways to hide information. One of the most powerful methods against data theft is steganography based on encryption using chaotic systems. Chaos systems are very sensitive to initial conditions. This makes it difficult to understand the password key easily. In this research, a system is designed to protect confidential data, which is represented by (image, sound), where the image is encrypted based on (Duffing chaotic map), and after encrypting it, it is hidden in the cover image and the sound is used as confidential information to be protected. This is done by encrypting the sound using (Modify Arnold Cat map), after that it will be hidden in the cover image. After that, the hidden data (stego image) is sent through a public channel. These messages are then retrieved in the receiver. The proposed method, creates a multi-level secure system. The simulation results also showed the possibility of using the proposed method in practical systems.

Enhanced pairwise IPVO-based reversible data hiding scheme using rhombus context

This paper proposes a new image steganographic method that effectively combines LSB embedding with Octa-PVD embedding. A cover image is divided into non-overlapping 3 × 3 sub-blocks, the n least significant bits of the center pixel of each sub-block is first substituted by secret data (n-LSB substitution). Then, the differences between the center pixel and its eight neighbors are calculated. For each direction, if the difference is equal or larger than a threshold (predefined by users or automatically determined by image analysis), secret data is embedded into the neighbor pixel by n-LSB substitution. Otherwise, secret data is embedded by PVD embedding, but into the neighbor pixel only. Consequently, depending on the conditions of each sub-block, a single embedding method can be used to the whole sub-block, or two embedding methods can be used alternately within a sub-block. Comparisons with existing LSB or multi-directional PVD embedding methods demonstrate that the proposed method has more optimized and higher embedding capacity and PSNR.


 
 
 A hybrid steganographic technique has been proposed to enlarge the size of secret message and to hide several images in one cover image. Initially, the secret images were compressed using JPEG 2000 before embedding them to the cover image. Second least significant bit plane of cover image was entirely replaced by secret message while tri-ways-pixel-value-differencing (TPVD) was used to hide secret message in remaining seven-bit cover image. The quality of stego image was enhanced by residual image coding (RIC). The cover image was divided in four sub-images, three of them provided cover for secret message using proposed technique while fourth sub-image was used to embed RIC of stego image using only TPVD, to ensure better quality in terms of peak signal to noise ratio (PSNR). Proposed technique provided the opportunity to transmit secret data without detection by different steganalysis techniques like dual statistics steganalysis. Experimental results verified that proposed technique achieved high payload with better image quality than TPVD scheme.
 
 

The aim of this study is to hide two binary BMP images in a single BMP grayscale image. The widespread technique in image steganography is to hide one image (stego image) into another (cover image). The proposed novel method is to hide two binary images into one grayscale bitmap cover image. First of all, the proposed technique starts with transforming all grayscale cover image pixels into multiples of five using Five Modulus Method (FMM). Clearly, any modulus of five is either 0, 1, 2, 3, or 4. The transformed FMM cover image could be treated as a good host for carrying data. Obviously, it is known that the pixel value for the binary image is either 0 or 1. Therefore, by concatenating the two binary images, the composite results are 00, 01, 10 and 11. In fact, these concatenated values could be mapped using simple mapping that assigns a positive integer value such as 1 for 00, 2 for 01, 3 for 10 and 4 for 11. Consequently, a new matrix will be constructed that contains a number varying from 1 to 4 only. Fortunately, the four integer values are the same as the previously mentioned reminders of division by 5, hence, adding these four integers to the transformed FMM cover image. On the recipient side, a reverse process will be implemented to extract the two binary images. In terms of PSNR values, the cover image and the two extracted stego images have acceptable PSNR values, which yields that the proposed method is very efficient in information hiding.