Large Embedding Research Articles

Data Hiding Based on Intelligent Optimized Edges for Secure Multimedia Communication

Recently, image steganography has received a lot of attention as it enables for secure multimedia communication. Payload capacity and stego image imperceptibility are a critical factors of any steganographic technique. In order to receive maximum embedding capacity with a minimum degradation of stego images, secret data should be embedded carefully in a specific regions. In this paper, data hiding is considered as an optimization problem related to achieving optimum embedding level of the cover image. Embedding data in edge area provide high imperceptibility. However, the embedding capacity of edge region is very limited. The work attempt to improve the edge based steganography by incorporates edge detection and vision science research. Genetic Algorithm that uses human visual system characteristics approach for data hiding is presented. Primarily, the approach applies Differences of Gaussian detector which closely resembles the human visual behavior. Secondly, the edge profusion indicates the level of threshold visibility with the help of Genetic Algorithm training. The suggested solution uses Contrast Sensitivity Function (CSF) which produces the edges based on the size of the embedding information. The authors of this paper compared their technique with other classical and recent works. The quality of the steganography is measured based on various quality metrics such as PSNR, wPSNR, SSIM and UIQI. These metrics declare the stability between imperceptibility and large embedding capacity.

A greedy steganographic SMVQ approach of greedy-USBIRDS using secret bits for image-block repairing based on differences

Steganography conceals the secret data into cover media to avoid detection, such that no one suspects the existence of the embedded secret data. The existing VQ-based and SMVQ-based steganographic methods can only provide the same level of visual quality of what the VQ/SMVQ compression method can offer. In this study, we present the idea of using secret bits to repair SMVQ-compressed images. The idea can be viewed as the optimization problem of Using Secret Bits for Image-block Repairing based on Differences under SMVQ (USBIRDS). We propose a novel approach named Greedy-USBIRDS to find a near optimal solution for the USBIRDS problem. The experimental results show that, the proposed method provides excellent stego-image quality and large embedding capacity, in particular for complex cover images such as Baboon. While compared with Chen and Lin's steganographic method, which is the known best method based on VQ/SMVQ, the proposed method achieves about 53 % more dB of PSNR of the stego-image quality and about 4.2 % more bits of the embedding capacity on average. All the experimental results indicate that, this study makes significant contributions to the area of VQ-based and SMVQ-based steganography, especially for its excellent stego-image quality and its ability to handle complex cover images very well.

A further study of large payloads matrix embedding

Matrix embedding (ME) is a well-known steganographic method that can improve the embedding efficiency. In ME, the sender and recipient agree in advance on a parity check matrix (PCM) of a binary linear code and utilize the PCM for data embedding. At the decoder side, the embedded message can be extracted by the recipient as the syndrome of the received stego data. The PCM can be taken as any full-ranked matrix and its selection is actually crucial to the embedding performance. In this paper, by extending some previous works, we propose a novel scheme to further improve the embedding efficiency of large payloads ME. First, we utilize a new and specifically designed matrix for ME. Then, instead of finding a coset leader as the modification to the cover which is time consuming, we turn to finding a vector in the coset with relatively small Hamming weight. By the proposed approach, effective and practically feasible large payloads ME can be realized, and extensive experiments show that, a significant increase of embedding efficiency is achieved compared with some state-of-the-art works.

A High-Capacity Covering Code for Voice-Over-IP Steganography

Although steganographic transparency and embedding capacity are considered to be two conflicting objectives in the design of steganographic systems, it is possible and necessary to strike a good balance between them in Voice-over-IP steganography. In this paper, to improve steganographic transparency while maintaining relatively large embedding capacity, the authors present a (2n-1, 2n) covering code, which can hide 2n-1 bits of secret messages into 2n bits of cover messages with not more than n-bit changed. Specifically, each (2n-1)-bit secret message is first transformed into two 2n-bit candidate codewords. In embedding process, the cover message is replaced with the optimal codeword more similar with it. In this way, the embedding distortion can be largely reduced. The proposed method is evaluated by comparing with existing ones with a large number of ITU-T G.729a encoded speech samples. The experimental results show that the authors' scheme can provide good performance on both steganographic transparency and embedding capacity, and achieve better balance between the two objectives than the existing ones.

MDE-based image steganography with large embedding capacity

The big data era calls for image steganography with large embedding capacity and good image quality. Previous methods described in the literature pay more attention to image quality rather than payload. This paper proposes a large capacity steganographic method based on modification direction exploitation and pixel pair matching. By virtue of a reference matrix with particular properties, one or two 9-ary digits can be embedded into each cover pixel pair depending on different payloads. Experimental results demonstrate high embedding capacity as well as good image quality and security. Copyright © 2015 John Wiley & Sons, Ltd.

Static and cyclic pullout behavior of cast-in-place headed and bonded anchors with large embedment depths in cracked concrete

The equipment of French nuclear power plants is fixed on reinforced concrete structures with base plate with headed fasteners. EDF decided to carry out an experimental research program in partnership with LGCIE in order to optimize the design of the headed fasteners and identify margin. This article introduces the results of pullout tests on anchors with large embedment cast in place in a reinforced concrete block. The anchorage are composed of an anchor plate welded to four ribbed bars or headed smooth studs. The studied parameters are: the type of loading (static or cyclic), the edge distance, the state of cracking of the concrete block. The anchors with headed rods or ribbed bars have a steel rod failure mode in agreement with their initial design. However, an optimization of the size on the headed anchors seems to be expected in order to improve their installation. This experimental campaign will provide a data base enabling the development of numerical models in order to improve the design.

An adaptive image steganographic scheme based on Noise Visibility Function and an optimal chaotic based encryption method

Steganography is the science of hiding secret message in an appropriate digital multimedia in such a way that the existence of the embedded message should be invisible to anyone apart from the sender or the intended recipient. This paper presents an irreversible scheme for hiding a secret image in the cover image that is able to improve both the visual quality and the security of the stego-image while still providing a large embedding capacity. This is achieved by a hybrid steganography scheme incorporates Noise Visibility Function (NVF) and an optimal chaotic based encryption scheme. In the embedding process, first to reduce the image distortion and to increase the embedding capacity, the payload of each region of the cover image is determined dynamically according to NVF. NVF analyzes the local image properties to identify the complex areas where more secret bits should be embedded. This ensures to maintain a high visual quality of the stego-image as well as a large embedding capacity. Second, the security of the secret image is brought about by an optimal chaotic based encryption scheme to transform the secret image into an encrypted image. Third, the optimal chaotic based encryption scheme is achieved by using a hybrid optimization of Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) which is allowing us to find an optimal secret key. The optimal secret key is able to encrypt the secret image so as the rate of changes after embedding process be decreased which results in increasing the quality of the stego-image. In the extracting process, the secret image can be extracted from the stego-image losslessly without referring to the original cover image. The experimental results confirm that the proposed scheme not only has the ability to achieve a good trade-off between the payload and the stego-image quality, but also can resist against the statistics and image processing attacks.

Anti-forensic steganography using multi-bit MER with flexible bit location

This work develops an anti-forensic steganography system using the proposed multi-bit MERs with flexible bit location embedding method multi-bit MER_FBL embedding method to overcome the problem of forensics and to achieve high performance including both large embedding capacity and high image quality. The proposed multi-bit MER_FBL embedding method hides multi-bit k-bit, k ≥ 1 logo/secret data into any adjoining starting with the ith location k-bit b

Numerical analysis with joint model on RC assemblages subjected to progressive collapse

The behaviour of structures subjected to progressive collapse is typically investigated by introducing column-removing scenarios. Previous experimental results show that large-deformation performances of reinforced concrete (RC) assemblages under a middle column removal scenario (MCRS) involve discontinuity due to bar slip and fracture near the joint interfaces. To consider the effects of the discontinuity on structural behaviour, a component-based joint model is introduced into macromodel-based finite-element analysis (macro-FEA), in which beams are modelled as fibre elements. The joint model consists of a series of non-linear springs, each of which represents a load transfer path from adjoining members to a joint. The calibration procedures of spring properties are illustrated systematically. In particular, a macro-bar stress–slip model is developed to consider the effects of large post-yield tensile strains and finite embedment lengths on the bar stress–slip relationship. Comparisons of simulated and observed responses for a series of RC assemblages indicate that macro-FEA incorporating the joint model is a practical approach to simulate the essential structural behaviour of RC assemblages under a MCRS, including catenary action. Finally, the macro numerical model is used to investigate the effects of boundary conditions, bar curtailment and beam depth on the structural behaviour of RC assemblages. The results suggest that beam depth affects the fixed-end rotation contributed by bar slip, and further significantly influences the development of catenary action.

Steganography Technique for JPEG2000 Compressed Images Using Histogram in Wavelet Domain

In this work, a steganography technique using histogram shifting for JPEG2000 compressed images is proposed. Histogram of the wavelet coefficients of each wavelet subband is calculated and shifted to embed secret image data. This embedding is performed on the peak wavelet coefficients during wavelet decomposition process of JPEG2000 encoder using Lifting scheme. Optimal Pixel Adjustment Process (OPAP) is performed on stego images to enrich their visual quality. The results given in this work show that proposed technique provide large embedding capacity and better visual quality of stego images than existing steganography techniques for JPEG2000 compressed images. Extracted secret image using proposed technique is similar to its original secret image.

Large capacity and high quality reversible data hiding method based on enhanced side match vector quantization

In recent years, many reversible data hiding techniques have been proposed to solve information security problem. In this paper, we propose a novel reversible data hiding method based on enhanced side-match vector quantization (ESMVQ). We embed as many secret bits into the images compressed by ESMVQ which uses the very small state codebook size of 4 to achieve a large hiding capacity and meanwhile ensure the compressed image quality by introducing a complementary state codebook. The experimental results demonstrate that the proposed method has a large embedding capacity and a good image quality. The experimental results also show that our proposed method outperforms the methods of Chang et al. (IEEE Trans on Circ and Syst for Vi Techno 16(10):1301---1308, 2006), Huang et al. (The Image Sci J 61(2):195---203, 2013), Lee et al. (IEEE Trans on Inf Forensic and Secur 5(4):638---648, 2010) and Wang et al. (Inf Sci 246:69---82, 2013).

Experimental and numerical investigation of uplift behavior of umbrella-shaped ground anchor

In the past decade, different types of underreamed ground anchors have been developed for substructures requiring uplift resistance. This article introduces a new type of umbrella-shaped anchor. The uplift behavior of this ground anchor in clay is studied through a series of laboratory and field uplift tests. The test results show that the umbrella-shaped anchor has higher uplift capacity than conventional anchors. The failure mode of the umbrella-shaped anchor in a large embedment depth can be characterized by an arc failure surface and the dimension of the plastic zone depends on the anchor diameter. The anchor diameter and embedment depth have significant influence on the uplift behavior. A finite element model is established to simulate the pullout of the ground anchor. A parametric study using this model is conducted to study the effects of the elastic modulus, cohesion, and friction angle of soils on the load-displacement relationship of the ground anchor. It is found that the larger the elastic modulus and the shear strength parameters, the higher the uplift capacity of the ground anchor. It is suggested that in engineering design, the soil with stiffer modulus and higher shear strength should be selected as the bearing stratum of this type of anchor.

Reversible Data Hiding in Encrypted Images Based on Image Interpolation

This paper proposes a novel method for data hiding in encrypted image using image interpolation. Before the image encryption, the original image is sampled and an interpolation algorithm is used to calculate an estimation of the original image. Errors between the original image and the estimated image are compressed by Huffman encoding, which are further embedded into the estimated image to generate the redundant room. After image encryption using an encryption key, the secret bits are embedded into the reserved room. On the receiver side, the hidden bits can be extracted and the original content of the image can be perfectly recovered. Compared with the published results, the proposed method provides a larger embedding payload.

Chaos-based Spatial Steganography System for Images

In this paper, we propose a chaos-based enhancement of two spatial steganographic algorithms; the AE-LSB and the EA-LSBMR and our objective is to study their performances. The first algorithm is an adaptive LSB (Least Significant Bit) steganographic method using pixel value difference that provides a large embedding capacity and imperceptible stego images. The second method is an edge adaptive scheme which can select the embedding region according to the size of secret message and the difference between two adjacent pixels in the cover image. The two methods suffer from low security against attacks that try to recover secret data.To overcome this weakness, we propose to enhance the message security of these methods. The enhancement consists of using an efficient chaotic system in order to choose in a pseudo-chaotic manner the pixels in the cover image where the bits of the secret message will be embedded. In this way, the inserted message becomes secure against message recovery attacks and becomes as well spread over the whole image in a uniform manner. Experiments show that the security of the algorithms is increased.

A novel data hiding for color images based on pixel value difference and modulus function

This paper proposes a novel data hiding method using pixel-value difference and modulus function for color image with the large embedding capacity(hiding 810757 bits in a 512×512 host image at least) and a high-visual-quality of the cover image. The proposed method has fully taken into account the correlation of the R, G and B plane of a color image. The amount of information embedded the R plane and the B plane determined by the difference of the corresponding pixel value between the G plane and the median of G pixel value in each pixel block. Furthermore, two sophisticated pixel value adjustment processes are provided to maintain the division consistency and to solve underflow and overflow problems. The most importance is that the secret data are completely extracted through the mathematical theoretical proof.

A novel image steganography scheme with high embedding capacity and tunable visual image quality based on a genetic algorithm

Steganography is knowledge and art of hiding secret data into information which is largely used in information security systems. Various methods have been proposed in the literature which most of them are not capable of both preventing visual degradation and providing a large embedding capacity. In this paper, we propose a tunable visual image quality and data lossless method in spatial domain based on a genetic algorithm (GA). The main idea of the proposed technique is modeling the steganography problem as a search and optimization problem. Experimental results, in comparison with other currently popular steganography techniques, demonstrate that the proposed algorithm not only achieves high embedding capacity but also enhances the PSNR of the stego image.

Secured Cryptography cum Steganography Model with Large Message Embedding behind Colored Image by using Genetic Algorithm and OPA Process

This paper introduced a combined cryptography and steganography model to increase the security and the embedding capability of the standard colored images. Cryptography is used in this technique to provide more security. For this purpose we used a secret key (same for sender and receiver) for encryption and decryption process. Only sender and receiver can encrypt and decrypt the whole message by this secret key. For steganography we use genetic algorithm, optimal pixel adjustment process, integer to integer wavelet transform in frequency domain, inverse integer to integer wavelet transform. Genetic algorithm is applied here to achieve a mapping function of 8*8 matrix with minimum error difference between the input and the final image. In GA we use the block based mapping method because by using it we can preserve the input image properties. After it we employed the optimal pixel adjustment process for increasing the hiding capacity of the proposed algorithm in comparison to other existing algorithms. OPA process adjusts all the pixels of image optimally. MATLAB simulation results present that the hiding capacity and imperceptibility of image increase simultaneously. By using the optimization technique such as GA we can choose the best block size to reduce the computation cost and also increase the peak signal to noise ratio.

A Joint Encryption and Reversible Data Hiding Scheme Based on Integer-DWT and Arnold Map Permutation

A joint encryption and reversible data hiding (joint encryption-RDH) scheme is proposed in this paper. The cover image is transformed to the frequency domain with integer discrete wavelet transform (integer DWT) for the encryption and data hiding. Additional data is hidden into the permuted middle (LH, HL) and high (HH) frequency subbands of integer DWT coefficients with a histogram modification based method. A combination of permutations both in the frequency domain and in the spatial domain is imposed for the encryption. In the receiving end, the encrypted image with hidden data can be decrypted to the image with hidden data, which is similar to the original image without hidden data, by only using the encryption key; if someone has both the data hiding key and the encryption key, he can both extract the hidden data and reversibly recover the original image. Experimental results demonstrate that, compared with existing joint encryption-RDH schemes, the proposed scheme has gained larger embedding capacity, and the distribution of the encrypted image with data hidden has a random like behavior. It can also achieve the lossless restoration of the cover image.

An Information Hiding Scheme Based on Pixel-Value-Ordering and Prediction-Error Expansion with Reversibility

This paper proposes a data hiding scheme based on pixel-value-ordering and predication-error expansion. In a natural image, most neighboring pixels have similar pixel values, i.e. the difference between neighboring pixels is small. Based on the observation, we may predict a pixel’s value according its neighboring pixels. The proposed scheme divides an image into non-overlapping blocks each of which consists of three pixels, and pixels in a block are sorted in a descending order. Messages are embedded into two difference values, where one is between the largest and medium pixels and the other is between the smallest and medium ones. In the embedding process, difference values equal to 0 or greater than 1 are unchanged or increased by 1, respectively, and those equal to 1 are also unchanged or increased by 1 if the message bit to be embedded is equal to 0 or 1, respectively. Calculating the difference value, one may extract a message bit of 0 or 1 if it is equal to 1 or 2, respectively. Recovering pixels is done by decreasing those difference values by 1 if they are equal to or larger than 2. Experimental results demonstrate that the proposed scheme may provide much larger embedding capacity, comparing to existing study, and a satisfied image quality.

NONLINEAR FE MODELLING OF ANCHORAGE BOND IN REINFORCED CONCRETE

The transfer of forces from the surrounding concret e to the reinforcing bars in reinforced concrete (R C) can be influenced by several parameters. In this paper an attempt has been made to study the influence of specimen geometry, bar di ameter, strength of concrete, lateral confinement and embedment length on the bon d properties of concrete. The embedment length of t he bar was varied between 50mm and 400mm by varying the diameter of the bar, strength of concrete and lateral confinement. The d ifferent bar diameters of 16, 20 and 25mm were selected along with three differen t concrete strengths of 25, 40 and 65MPa. The speci mens with the above parameters were modeled by using a nonlinear finite element analysis package. It has been found that fthe same geometry, the specimens with small bond length exhibited high bon d strength. With the range of bar diameters conside red the bond strength of concrete decreases as the diameter of the bar incre ases. The splitting failure has been observed in un confined concrete, while the pullout failure was predominant when the concrete l aterally confined. In case of large embedment lengt h, the post peak plateau is prolonged with small diameter bars when compared to the large diameter bars. The descending branch of the bond stress-slip response with large diameter bars has been found to be steep.