Large Embedding Capacity Research Articles

A generative method for steganography by cover synthesis with auxiliary semantics

Traditional steganography is the practice of embedding a secret message into an image by modifying the information in the spatial or frequency domain of the cover image. Although this method has a large embedding capacity, it inevitably leaves traces of rewriting that can eventually be discovered by the enemy. The method of Steganography by Cover Synthesis (SCS) attempts to construct a natural stego image, so that the cover image is not modified; thus, it can overcome detection by a steganographic analyzer. Due to the difficulty in constructing natural stego images, the development of SCS is limited. In this paper, a novel generative SCS method based on a Generative Adversarial Network (GAN) for image steganography is proposed. In our method, we design a GAN model called Synthetic Semantics Stego Generative Adversarial Network (SSS-GAN) to generate stego images from secret messages. By establishing a mapping relationship between secret messages and semantic category information, category labels can generate pseudo-real images via the generative model. Then, the receiver can recognize the labels via the classifier network to restore the concealed information in communications. We trained the model on the MINIST, CIFAR-10, and CIFAR-100 image datasets. Experiments show the feasibility of this method. The security, capacity, and robustness of the method are analyzed.

Reversible Data Hiding in Encrypted Image Based on Multi-MSB Embedding Strategy

In this paper, a reversible data hiding method in encrypted image (RDHEI) is proposed. Prior to image encryption, the embeddable pixels are selected from an original image according to prediction errors due to adjacent pixels with strong correlation. Then the embeddable pixels and the other pixels are both rearranged and encrypted to generate an encrypted image. Secret bits are directly embedded into the multiple MSBs (most significant bit) of the embeddable pixels in the encrypted image to generate a marked encrypted image during the encoding phase. In the decoding phase, secret bits can be extracted from the multiple MSBs of the embeddable pixels in the marked encrypted image. Moreover, the original embeddable pixels are restored losslessly by using correlation of the adjacent pixels. Thus, a reconstructed image with high visual quality can be obtained only when the encryption key is available. Since exploiting multiple MSBs of the embeddable pixels, the proposed method can obtain a very large embedding capacity. Experimental results show that the proposed method is able to achieve an average embedding rate as large as 1.7215 bpp (bits per pixel) for the BOW-2 database.

A Reversible Data Hiding Algorithm Based on Prediction Error With Large Amounts of Data Hiding in Spatial Domain

In recent years among data hiding technologies, Reversible Data Hiding(RDH) technology has attracted widespread interest and application, which is to hide the secret information in a carrier image and recover the original carrier image losslessly to extract the secret information. Current research on RDH algorithms mainly involving frequency domain, spatial domain, and encryption domain. Based on the Prediction-Error Expansion(PEE) methods, as spatial domain approaches, achieved great progress in the past decade. However, there is a defect in the state-of-the-art methods that with the embedded payload increased, the distortion rate of the cover image increased simultaneously. To solve the problem, we proposed a refined reversible data hiding algorithm based on the PEE method with simple implementation. We improved an effective predictor that all the remaining pixels can be predicted in the embedding process, except for those in the first row, the first column, the last row, and the last column in the original image. The extraction process is the reverse of the embedding process that the embedded information and the original carrier is restored without damage. Our work utilized the correlation between image pixels better to solve the inherent contradiction between payload and distortion rate in the state-of-the-art data hiding algorithms. Proven through experiments, our method achieved a large embedding capacity while keeping the image distortion rate and computing complexity low.

Video Steganography using IWT, DWT, LBP Methods and its Comparative Research

Steganography is a method used for inserting the secret information into an another medium such as text, images, audio signals or video signals, without revealing its existence in the medium. In video steganography, a video file will be used as a cover medium and secret message embedded inside the cover medium. Video are picture perfect for embedding the secret message because of its large embedding capacity. We propose three secure steganography algorithms that embed a bit stream of the secret message into the approximation coefficients of the integer wavelet transform(IWT), DWT and using LBP method to form stego video. The geometric alteration between the cover video and the stego video is measured by using the Mean Square Error (MSE) and the PSNR. The new results show that, the proposed algorithms can hide the secret message with a great payload capacity with a high level of security and a greater invisibility.

Reversible data hiding in encrypted images using adaptive reversible integer transformation

Reversible data hiding in encrypted images (RDH-EI) is a technique that hides additional data into the ciphertext with a capability of recovering the original content losslessly. In recent years, many methods have been proposed on this topic. In this paper, we propose a new RDH-EI approach that can achieve a very large embedding capacity, using adaptive reversible integer transformation. We first divide the original image into non-overlapped blocks. With an algorithm of adaptive reversible integer transformation, we vacate the embedding room for accommodating the auxiliary data and the payload. After image encryption and uploading, the cloud server can hide a large amount of additional data into the ciphertext using the embedded auxiliary data. The process is reversible that the additional data can be extracted exactly and the original image can be recovered without any error. Compared with state-of-the-art RDH-EI methods, the proposed method can achieve a much higher embedding capacity and a better rate distortion performance.

A Reversible Data Hiding with Quality Controllable Scheme for Encrypted-Compressed Image

In order to achieve image encryption and data embedding simultaneously, a reversible data hiding (RDH) algorithm for encrypted-compressed image in wavelet domain is proposed. This scheme employs the quality controllable parameter. Moreover it has larger embedding capacity and smaller quality control parameters than other methods in literatures. Meanwhile, the cross chaotic map is employed to generate chaotic sequences, and the total keys of the algorithm is far large. Experimental results and comparisons show that the proposed scheme has large capacity, high security, and strong resistance to brute-force.

Extended squared magic matrix for embedding secret information with large payload

Data hiding is a technology designed for safely transmitting secret data through open communication channels, in which the secret data are embedded into a cover carrier imperceptibly. Among the existing data hiding schemes, the exploiting-modification-direction (EMD) based schemes draw considerable attentions due to large embedding capacity. The proposed scheme improves the EMD-2 scheme by constructing an extended squared magic matrix, resulting in a larger embedding capacity high up to 3.15 bits per pixel (bpp). Experimental results show that the proposed scheme outperforms state-of-the-art reference matrix based schemes in terms of embedding capacity, meanwhile, maintains good image quality.

Adaptive Reversible Data Hiding Scheme for Digital Images Based on Histogram Shifting

Existing histogram based reversible data hiding schemes use only absolute difference values between the neighboring pixels of a cover image. In these schemes, maxima and minima points at maximum distance are selected in all the blocks of the image which causes shifting of the large number of pixels to embed the secret data. This shifting produces more degradation in the visual quality of the marked image. In this work, the cover image is segmented into blocks, which are classified further into complex and smooth blocks using a threshold value. This threshold value is optimized using firefly algorithm. Simple difference values between the neighboring pixels of complex blocks have been utilized to embed the secret data bits. The closest maxima and minima points in the histogram of the difference blocks are selected so that number of shifted pixels get reduced, which further reduces the distortion in the marked image. Experimental results prove that the proposed scheme has better performance as compared to the existing schemes. The scheme shows minimum distortion and large embedding capacity. Novelty of work is the usage of negative difference values of complex blocks for secret data embedding with the minimal number of pixel shifting.

Hybrid Adaptive Video Steganography Scheme Under Game Model

The steganographic model based on game theory is improved. A hybrid steganography model that satisfies the Kerckhoffs principle by combining the strategy adaptation of the game theory model and the content adaptation in the cover model is proposed. This model is used to design a high-security steganography algorithm for an H.264 video. The distortion function in UNIWARD algorithm is improved according to the H.264 video coding characteristics. The improved distortion function is used to generate the bias function under the game theory model, and the embedding probability of each position in the cover is calculated. The new distortion function under the hybrid model is generated by combining the embedding probability of the cover position and the distortion cost function under the improved UNIWARD algorithm and using it to embed information in the H.264 residual DCT coefficient block. The experiment proves that the algorithm has higher security than the UNIWARD algorithm. With the same analysis algorithm, the detection error rate is significantly improved compared to the UNIWARD algorithm. The algorithm has a large embedding capacity and good invisibility. When fully embedded, the capacity reaches 1.9% or more, the visual effect does not change significantly, and the PSNR value decreases within 2 dB. After the secret message is embedded in the information, the video bit rate is increased by 9%.

Protection of Ultrasound Image Sequence: Employing Motion Vector Reversible Watermarking

In healthcare information systems, medical data is very important for diagnosis. Most of the health institutions store their patients’ data on third-party servers. Therefore, its security is very important, since the advent of advanced multimedia and communication technology, whereby digital contents are manipulated, copied, and duplicated without leaving any trace. In this paper, a reversible watermarking technique is applied to the patients’ data (ultrasound image sequence). Since the traditional watermarking schemes can experience some permanent distortions that are not acceptable in the medical application. Thus, a reversible watermarking technique has been used, which can not only secure the ultrasound image sequence but also restore the original sequence back. For watermark embedding, the magnitude and phase angles of motion vectors of the image sequence are used that are obtained by using Full-Search block-based motion estimation algorithm. Before applying the motion estimation algorithm and watermark embedding, the histogram pre-processing is performed to avoid underflow/overflow. Unlike other state-of-the-art watermarking schemes that are reported in the last decades, the experimental results show that the proposed algorithm is simple, provides a much larger embedding capacity and better quality of the watermarked image sequence.

An adaptive reversible data hiding scheme using dual stego-image

ABSTRACT To enhance the embedding capacity and restore the cover images without any distortion, a reversible data hiding technique which hides secret data into two identical images simultaneously is proposed. With regard to the Exploiting Modification Direction (EMD) based techniques, irreversible data hiding technique hides at least 1 bpp and the resulting PSNR of stego-images is about 45 dB. The EMD-based reversible data hiding techniques adopt two cover images to hides base-5 numerals and the resulting PSNR value of stego-images is about 45–47 dB. This paper proposes a reversible data hiding scheme based on the Adaptive Exploiting Modification Direction (AEMD) formula to adjust the embedding capacity and image quality. We can manipulate an adjustable parameter to gain a higher image quality or a larger embedding capacity, depending on various demands of users. The experimental results show that the proposed scheme achieves a higher image quality with the same embedding capacity compared with previous methods.

Real-time adaptive visual secret sharing with reversibility and high capacity

Visual secret sharing is an efficient technique for the protection of real-time message transmissions. For the sake of security enhancement, the data hiding-based visual secret sharing (DH-VSS) methods are emerging and have gained considerable research attention in recent years. However, although most of the existing DH-VSSs are real-time algorithms, the computational complexity for a typical DH-VSS scheme still needs to be improved. Therefore, in this paper, we propose a more efficient real-time $$(2,2)$$ DH-VSS scheme based on the least-significant-bit (LSB) substitution technique with large embedding capacity. The original cover image is divided into eight bit planes in such a way that the secret messages are embedded in the 3-LSB bit planes to create two meaningful shadow images. This is an adaptive method since extra secret bits can be embedded into the fourth LSB bit plane of the first shadow image, depending on whether the currently processed pixel is in a smooth or complex block. The embedded secret messages can be losslessly extracted by the cooperation of both shadows; the original cover image can also be exactly restored. Experimental results show that the computational complexity of the proposed DH-VSS scheme is significantly lower than that of related state-of-the-art methods. Furthermore, its embedding capacity is greatly enhanced under less execution time. Therefore, the proposed scheme is computation efficient as well as practical so as to be quite suitable for diverse real-time applications.

Targeted attack and security enhancement on texture synthesis based steganography

We describe an effective and efficient strategy building steganography detector for patch synthesis based steganography, one case of which is reversible texture synthesis based steganography method proposed by Wu et al. (2015). By exploiting the observation that steganography destroys optimization of matching extent between the synthetic patch and optimal candidate patch, we reconstruct the two patches from an overlapped region to extract the existence of optimality, which are distinct between cover and stego images, to form features. Support vector machine (SVM) is implemented for classification. Meanwhile, a variant of Wu et al.’s steganographic method is proposed with reinforced security, by padding redundant regions carrying no message around the periphery of the synthesized image and generating additional candidate patches to increase capacity. Experiments demonstrate that the modified algorithm offers not only better resistance against the state-of-the-art steganalysis methods and steganalytic attack we developed, but also a larger embedding capacity.

Global resynchronization-based image watermarking resilient to geometric attacks

How to resist geometric attacks effectively and improve the watermark embedding capacity are still challenging tasks. An algorithm with better capabilities to resist cropping and combined attacks, as well as having a larger embedding capacity, is proposed. Feature points from the attacked image are obtained with the Speeded-Up Robust Features (SURF) algorithm. Then, they are matched with a few feature points obtained from the watermarked image. The matching point pairs are used to estimate the affine matrix, and then the geometric attacks are corrected by the inverse affine transform. Some positioning watermarks are embedded in the spatial domain to improve the accuracy of the resynchronization. Finally, the watermark is encoded by the fountain code such that the anti-cropping performance of the algorithm can be improved. The experimental results show that the proposed algorithm not only has a larger embedding capacity but also is resistant to many kinds of attacks.

Secure and robust digital image watermarking scheme using logistic and RSA encryption

In the era of big data and networking, it is necessary to develop a secure and robust digital watermarking scheme with high computational efficiency to protect copyrights of digital works. However, most of the existing methods focus on robustness and embedding capacity, losing sight of security or requiring significant computational resources in the encryption process. This paper proposed a new digital image watermarking model based on scrambling algorithm Logistic and RSA asymmetric encryption algorithm to guarantee the security of the hidden data at the foundation of large embedding capacity, good robustness and high computational efficiency. The experiments involved applying the encryption algorithms of Logistic and RSA to the watermark image and performing the hybrid decomposition of Discrete wavelet transform (DWT) and Singular Value Decomposition (SVD) on the host image, and the watermark was embedded into the low-frequency sub-band of the host. The values of PSNR and NCC were measured to estimate the imperceptibility and robustness of the proposed watermarking scheme, and the CPU running time was recorded to measure the complexity of the proposed main algorithm in execution time. Experimental results showed the superiority of the proposed watermarking scheme.

An efficient data hiding method based on adaptive directional pixel value differencing (ADPVD)

Steganography is an important secret information communication technology in which one may send messages without others having knowledge of their existence. This paper proposes a new adaptive steganography method for color images using adaptive directional pixel-value differencing (ADPVD). The proposed method increases the capacity of the hidden secret data and improves the security of the stego-color image as well. The hiding capacity of the original PVD method is investigated by considering three directional edges: horizontal, vertical and diagonal directions using color cover image. The cover image is partitioned into 2-pixel blocks in a non-overlapping fashion and scanned in raster-scan order in all three directions. The proposed method adaptively selects the appropriate embedding directions for each color channel according to the largest embedding capacity. The security is improved since different pixel directions are employed adaptively to embed different number of message bits in each color channel. The experimental results show that the proposed method provides both larger embedding capacity and better visual quality of the stego color image compared with other PVD-based algorithms.

EMD-based steganography techniques for JPEG2000 encoded images

In JPEG2000 standard, the number of bit planes of wavelet coefficients to be used in encoding is dependent on the compression ratio as well as subbands. These significant wavelet bit planes can be utilized to embed bits of secret data as they are retained in the final bit stream after Tier-2 encoding. In proposed techniques, the above mentioned concept have been utilized to embed secret data bits in lowest significant bit planes of the quantized wavelet coefficients of a cover image. In first technique, secret data is converted into a series of symbols using multiple bases notational system. These bases are selected by using the degree of local variation of coefficient values of the cover image so that coefficient of a complex region can potentially carry more secret data bits as compared to coefficients of smooth region. Symbols of secret data are embedded into bit planes of significant quantized wavelet coefficients by using EMD approaches. In second technique, the secret data bits are embedded into significant quantized wavelet coefficients by using modified EMD. Experimental results show that these proposed techniques provide large embedding capacity and better visual quality stego images than existing steganography techniques applicable to JPEG2000 compressed images. It has also been shown that modified EMD-based technique is better than EMD with multiple bases notational system (MBNS)-based technique.

Obtuse Angle Prediction and Factor Evaluation for Image Reversible Data Hiding

A pixel-based pixel-value-ordering (PPVO) has been used for reversible data hiding to generate large embedding capacity and high-fidelity marked images. The original PPVO invented an effective prediction strategy in pixel-by-pixel manner. This paper extends PPVO and proposes an obtuse angle prediction (OAP) scheme, in which each pixel is predicted by context pixels with better distribution. Moreover, for evaluating prediction power, a mathematical model is constructed and three factors, including the context vector dimension, the maximum prediction angle, and the current pixel location, are analyzed in detail. Experimental results declare that the proposed OAP approach can achieve higher PSNR values than PPVO and some other state-of-the-art methods, especially in the moderate and large payload sizes.

Enhancing the Performance of the Data Embedment Process through Encoding Errors

Image steganography is a multipurpose-serving key emerging technology that is used for covertly transferring, storing, and governing various digital data, including intellectual properties and copyrights, social media data, multimedia data, and secrets of law-enforcing agencies. During the management in the stated information, nowadays, massive amounts of data are handled that require greater security. For that purpose, data are embedded into a cover image to hide them from any intruders. Nevertheless, the requirements of a larger embedding capacity, improved stego-image quality, and reduced time complexity is increasing. In this paper, the authors have presented a novel data-embedding scheme where the prediction error-based data-hiding scheme is modified in an intricate way so that all the image pixels can accept secret bits. A distance matrix between the pixel values of each image block and a reference value are measured first. Thereafter, the distances are encoded into two states: 1 and −1. That encoding process enables the scheme to implant one bit in every pixel of the cover image. During the bit implantation, the errors 1 and −1 are modified by shifting them to the right and left directions, respectively. This strategy enhances the embedding capacity by a factor of more than 2. The use of reference values reduces the computational complexity notably, and in the meanwhile increases the security and robustness of the scheme because the reference values are not open to any third party. The scheme also reduces the time complexity by 2–16 times with compared to its competing schemes. Experimental results prove the superiority of the proposed algorithm on embedding capacity, visual quality, and time complexity compared to the current well-accepted existing schemes.

A Characteristic-Preserving Steganographic Method Based on Revision Identifiers

Since the majority of the available steganographic schemes in OOXML format documents suffered the disadvantages of unsatisfactory anti-detection capability and security level, a characteristic-preserving steganographic method with high security is proposed in this paper. The proposed method embeds secret information by replacing the last three bytes of the values of the revision identifiers in the main document body of the OOXML format document, while preserving the normal characteristics of the document. Meanwhile, position marks are added to track the locations of the embedded information. In order to keep the internal data consistency of the document, the newly created values are added into other related parts. Experimental results show that the method not only possesses good imperceptibility and anti-detection capability, but also has high security and large embedding capacity.