Separable reversible data hiding in encrypted images based on scalable blocks

This paper proposes a new separable reversible data hiding method for encrypted images. Proposed scheme employs the pixel redundancy of natural images to construct embedding space. First, cover image is divided into multiple blocks with different scales. According to the pixel average value of each block, the lowest two bits of every pixel are vacated as reserved rooms. Subsequently, the whole image is encrypted by using stream cipher and the secret messages are finally embedded into the reserved rooms by the embedding key. Proposed scheme is separable in the sense that the recipient can achieve different function by the following ways: (a) If the recipient has only decryption key, an approximation plaintext image containing the embedded information can be obtained. (b) If the recipient has only embedded key, secret messages can be extracted correctly. (c) If the recipient has both decryption key and embedded key, he can not only extract the secret messages, but recover the original cover image perfectly. Extensive experiments are performed to show that our proposed schemes outperform existing reversible data hiding schemes in terms of visual quality, embedding capacity and security performance, even if a large-scale image database is used.

     

全体变长编码映射的JPEG可逆信息隐藏

目的 JPEG(joint photographic experts group)作为一种广泛使用的图像格式,对其进行可逆信息隐藏有实际应用价值。大多数以JPEG图像为载体的可逆信息隐藏方案会导致图像质量降低和文件膨胀。由于在JPEG比特流中,并没有使用较多的变长编码(variable-length code, VLC),因此以未使用的VLC替换已使用的VLC可以实现秘密信息的无损嵌入,但这类方法的嵌入容量有限,且会导致文件膨胀。为了实现更大的嵌入容量并更好地控制文件膨胀,本文提出了新的全体VLC映射方案。方法 首先,重排序原始比特流中的行程长度/幅值大小(run/size value, RSV),获得去除编码冗余的载体;然后,引入中间VLC的概念,根据VLC频数分布,确定使文件膨胀大小相对于嵌入载荷最小的最优中间VLC映射模型;接着,通过计算模拟嵌入下的文件膨胀大小,确定构建最优中间VLC映射所需的嵌入VLC和中间VLC集合;最后,根据最优中间VLC映射关系修改定义哈夫曼表和JPEG比特流实现秘密信息的嵌入。结果 实验在USC-SIPI数据库上与基于DCT(discrete cosi...     

An optimal high capacity reversible data hiding scheme using move to front coding for LZW codes

Reversible Data hiding techniques reduce transmission cost as secret data is embedded into a cover image without increasing its size in such a way that at the receiving end, both secret data and the cover image can be extracted and recovered, respectively, to their original form. To further reduce the transmission cost, the secret data can be embedded in the compression codes by some popular reversible data hiding schemes. One of the popular and important reversible data hiding method is high- performance data-hiding Lempel–Ziv–Welch (HPDH-LZW) scheme which hides the secret data in LZW codes. In this paper, the HPDH-LZW scheme is modified in order to increase its hiding capacity and compression ratio. First, the proposed work modifies the Move to Front (MTF) encoding technique to hide the secret data and also to increase the similarity among the element of the cover media. Then, LZW encoding technique is applied on the resultant cover data to obtain LZW codes, which are used to hide further secret data. Experimental results show that the proposed scheme has significantly increased the data hiding capacity and have good embedding and extraction speed in comparison to other state of the art schemes.

     

Reversible steganography based on side match and hit pattern for VQ-compressed images

Data hiding is an important technique in multimedia security. Multimedia data hiding techniques enable message senders to disguise secret data by embedding them into cover media. Thus, delivering secret messages is as easy as sending the cover media. Recently, many researchers have studied reversible data hiding for images. Those methods can reconstruct the original cover image and extract the embedded secret data from a stego-image. This study proposes a novel reversible steganographic method of embedding secret data into a vector quantization (VQ) compressed image by applying the concept of side match. The proposed method uses extra information, namely the hit pattern, to achieve reversibility. Moreover, its small hit pattern enables the embedding of the entire hit pattern along with the secret data in most cases. To optimize visual quality of the output stego-image, the method applies the concept of partitioned codebooks (state codebooks). The partition operation on the codebook uses a look-up table to minimize embedding and extraction time. We also propose the use of diagonal seed blocks to embed the entire hit pattern into the cover image without producing any extra control messages. Compared to the Chang and Lin method, the experimental results show that the proposed method has higher capacity, better visual quality, and shorter execution time.     

Reversible data hiding in compressed and encrypted images by using Kd-tree

In this paper, a joint scheme and a separable scheme for reversible data hiding (RDH) in compressed and encrypted images by reserving room through Kd-tree were proposed. Firstly, the plain cover image was losslessly compressed and encrypted with lifting based integer wavelet transform (IWT) and set partition in hierarchical tree (SPIHT) encoding. Then, several shift operations were performed on the generated SPIHT bit-stream. The shifted bit-stream was restructured into small chunks and packed in the form of a large square matrix. The binary square matrix was exposed to Kd-tree with random permutations and reserving uniform areas of ones and zeros for secret data hiding. After that, a joint or a separable RDH scheme can be performed in these reserved spaces. In the joint RDH scheme, the secret data were embedded in the reserved spaces before encrypting with multiple chaotic maps. Thus, secret data extraction and cover image recovery were achieved together. In the separable RDH scheme, the secret data were embedded in the reserved spaces after encrypting with multiple chaotic maps. Since message extraction and cover image recovery are performed separately, anyone who has the embedding key can extract the secret message from the marked encrypted copy, while cannot recover the cover image. A complete encoding and decoding procedure of RDH for compressed and encrypted images was elaborated. The imperceptibility analysis showed that the proposed methods bring no distortion to the cover image because there was no change to the original cover image. The experimental results showed that the proposed schemes can perform better for secret data extraction and can restore the original image with 100% reversibility with much more embedding capacity and security. The proposed schemes significantly outperform the state-of-the-art RDH methods in the literature on compressed and encrypted images.

     

基于BitTorrent协议Have消息的信息隐藏方法

针对以比特流（BitTorrent）协议消息为载体的信息隐藏算法在隐蔽性和嵌入容量上所存在的问题,提出一种以Have消息序列为载体的信息隐藏方法。首先,在秘密信息嵌入前设置容量分析模块,判断信息嵌入量是否超出信息隐藏容量上限;其次,在信息嵌入时使用改进的奇偶映射信息编码方式,将秘密信息嵌入到Have消息的排序中;最后,在信息提取时引入循环冗余校验（CRC）方法,验证秘密信息是否传输正确。实验结果表明,相比原有的奇偶映射编码方式,所提方法的嵌入容量明显提高,且通过对Have序列统计特性的分析,所提方法对Have序列统计特性的影响较小,隐蔽性较强。     

基于BMP图像数据的信息隐藏方法

提出了一种通过增加BMP图像数据实现信息隐藏的方法.BMP图像的显示是根据文件头数据来确定图像数据的,与文件中图像数据以后的数据没有关系,将秘密信息嵌入到图像数据以后的字节中,只是增加了BMP文件的大小,并不影响图像的显示,从而实现信息隐藏.按照秘密信息的数据大小,从载密图像中读出秘密信息的字节数据,即可恢复秘密信息.该算法简单易行,载密图像和原图像在视觉上没有任何差别,具有较强的隐蔽性.仿真结果证明了算法的可行性和有效性.     

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.

     

A new high capacity and secure image realization steganography based on ASCII code matching

Digital Steganography is the art of hiding secret messages behind an innocent looking digital media that do not raise suspicions. In this paper, a new proposed image realization steganography method is introduced which is a mapping-based method that hides in an unrevealed manner and without any change in the image cover file. The image cover is only used for referencing. The proposed method generates the cover-secret mapping that will realize the concealed secret message without embedding the real message. A mapping between the American Standard Code of Information Interchange (ASCII) codes of a secret message and an image is performed and the positions of the secret message in the image is noted in a position array. This reference positions are then sent to the receiver after first being compressed by Huffman algorithm and then encrypted using Advanced Encryption Standard with 128 bits key (AES-128). The position array and the cover image are transferred separately, so that the interception of any one file alone will not conceal any information. In addition, it has unlimited capacity as specific matching positions can be used more than once. Furthermore, the proposed method has a reduced size of position key and mapping table, hence having high-speed searching and matching compared to prevailing methods. Furthermore, several experimental tests have been applied to assess the efficiency and performance of the new proposed method to evaluate it according to the widely used metrics: Mean Squared Error (MSE) and Peak Signal to Noise Ratio (PSNR). From the security point of view, Structural Similarity Index Measure (SSIM) together with Histogram have been performed. Moreover, it is critiqued showing its pros and cons and further compared with existing state-of-the-art research. The experimental results verified the efficacy of the new proposed method.

     

利用像素置换的自适应可逆信息隐藏

目的 像素置换作为一种可逆信息隐藏方式具有良好的抗灰度直方图隐写分析能力,但嵌入容量偏小一直是其缺陷。针对这一问题,提出了一种基于像素置换的自适应可逆信息隐藏算法。方法 首先,与传统2×2像素块结构相比构造了尺寸更小的像素对结构,使得载体图像可以被更稠密地分割,为嵌入容量的提升提供了基数条件。其次,提出适用于该新像素结构的可嵌像素对（EPP）筛选条件,避免嵌入过程引起图像质量大幅下降。之后,根据EPP的灰度趋势差异对其进行自适应预编码,提高Huffman编码压缩比,进一步提升算法嵌入容量。最终,通过像素置换嵌入信息。结果 与2×2像素块结构的非自适应图像隐写算法相比,在同样保证灰度直方图稳定性的情况下该算法的PSNR提高了32%左右,嵌入容量提高了95%以上。其中自适应性对嵌入容量提升的贡献极大。结论 本文算法同时具有抗灰度直方图隐写分析能力与高嵌入容量性的可逆信息隐藏。算法构造了更高效的可嵌单位,并且针对不同载体图像的特点对其可嵌区域进行差异化编码。实验结果表明,本文算法在具有更好的不可见性的同时,嵌入容量得到大幅提升。     

完全质量保持的AVS视频可逆信息隐藏算法

可逆信息隐藏在医学资料管理、法律取证等领域有广泛的应用。提出一种以AVS视频为载体的可逆信息隐藏算法,通过同时修改宏块的量化参数和DCT量化系数实现信息的嵌入。算法不仅在提取出嵌入信息后能完全恢复出原始载体视频,而且信息的嵌入不会对载体视频的视觉质量造成任何损失。为了解决算法引起的码率扩张问题,在RZL(reverse zerorun length)编码的基础上提出IRZL(improved RZL)编码方法。实验结果表明,新编码方法能有效抑制码率扩张。在中等及大嵌入率的情况下,IRZL编码比RZL编码的效果更好。     

A reversible data hiding scheme based on the Sudoku technique

Data hiding, also known as information hiding, plays an important role in information security for various purposes. Reversible data hiding is a technique that allows distortion-free recovery of both the cover image and the secret information. In this paper, we propose a new, reversible data hiding scheme that is based on the Sudoku technique and can achieve higher embedding capacity. The proposed scheme allows embedding more secret bits into a pair of pixels while guaranteeing the good quality of the stego-image. The experimental results showed that the proposed scheme obtained higher embedding capacity than some other previous schemes. In addition, our proposed scheme maintained the good visual quality of the stego-image (i.e., PSNR > 46 dB), which outperforms some existing schemes.     

Data hiding based on overlapped pixels using hamming code

Most data hiding schemes change the least significant bits to conceal messages in the cover images. Matrix encoding scheme is a well known scheme in this field. The matrix encoding proposed by Crandall can be used in steganographic data hiding methods. Hamming codes are kinds of cover codes. “Hamming + 1” proposed by Zhang et al. is an improved version of matrix encoding steganography. The embedding efficiency of “Hamming + 1” is very high for data hiding, but the embedding rate is low. Our proposed “Hamming + 3” scheme has a slightly reduced embedding efficiency, but improve the embedding rate and image quality. “Hamming + 3” is applied to overlapped blocks, which are composed of 2^k+3 pixels, where k=3. We therefore propose verifying the embedding rate during the embedding and extracting phases. Experimental results show that the reconstructed secret messages are the same as the original secret message, and the proposed scheme exhibits a good embedding rate compared to those of previous schemes.     

Image steganography using deep learning based edge detection

This paper introduces a deep learning-based Steganography method for hiding secret information within the cover image. For this, we use a convolutional neural network (CNN) with Deep Supervision based edge detector, which can retain more edge pixels over conventional edge detection algorithms. Initially, the cover image is pre-processed by masking the last 5-bits of each pixel. The said edge detector model is then applied to obtain a gray-scale edge map. To get the prominent edge information, the gray-scale edge map is converted into a binary version using both global and adaptive binarization schemes. The purpose of using different binarization techniques is to prove the less sensitive nature of the edge detection method to the thresholding approaches. Our rule for embedding secret bits within the cover image is as follows: more bits into the edge pixels while fewer bits into the non-edge pixels. Experimental outcomes on various standard images confirm that compared to state-of-the-art methods, the proposed method achieves a higher payload.

     

A survey of interpolation-based reversible data hiding methods

It is called as a reversible data hiding method when the cover object can be restored together with extracting the secret data at a receiver. In reversible data hiding, interpolation-based data hiding methods are recently proposed, where image interpolation techniques are used before embedding the secret data. In this paper, reversible data hiding methods using interpolation techniques are described and analyzed on the embedding capacity and the visual image quality that many researchers have tried to improve these different measurements. It is concluded with the directions of research with some recommendations.     

High capacity information hiding for privacy protection in digital video files

In this paper, a framework to hide privacy in video is proposed based on data hiding principals. A novel data hiding technique is proposed and implemented to hide the original frame into the in-painted one. The proposed hiding technique is carried out in the discrete wavelet transform domain of the cover video. The proposed technique is embedding video into video. Furthermore, the proposed data hiding method can blindly reconstruct the original frame from the fake one. Experimental results showed that the proposed method can successfully hide the complete frames of the original video into their corresponding in-painted ones that are as large as themselves. Simple visual inspection of the results showed that the quality of the stego-frames maintain very high (above 45 dB) while providing an acceptable visual quality for the retrieved original frames.

     

基于图像LSB的秘密信息隐藏技术

基于图像的信息隐藏技术有着广泛的应用,而最低有效位算法是其中有效的方法之一.本文首先对载体图像进行位平面分析,发现LSB位具有最好的隐藏效果;然后分别实现了三个以二值图像和文本文件作为秘密信息的信息隐藏和提取实验.实验结果表明：基于图像LSB的秘密信息隐藏不仅具有算法简单、透明性良好的特点,而且还具有隐藏信息容量大、无失真提取、对文本文件具有双重隐藏功能等优点.     

Lossless data hiding in JPEG bitstream

This paper proposes a method of embedding secret data into JPEG bitstream by Huffman code mapping. Although JPEG defined 162 different variable length code (VLC) for AC coefficients, many codes are not used during image compression. According to the statistical results of VLC usage in a cover, we map the unused codes to used codes. The relationships of code mapping are performed by modifying the Huffman values defined in the file header. During data hiding, we replace the codes appearing in bitstream by the mapped codes according to the secret bits. The proposed embedding method preserves the image with no quality distortion and provides more embedding capacity.     

基于四边边缘匹配的图像信息隐秘法

将人眼的视觉特性和图像信息隐藏技术结合,文章提出了基于HVS特性的信息隐秘方法,设计实现了一种基于四边边缘匹配的自适应信息隐秘算法,利用嵌入信息像素相邻的四个像素信息估计嵌入容量,依据载体图像局部的不同特性自适应地隐藏秘密信息.实验结果表明,这种方法比最低有效位算法嵌入容量大,而且不会产生易觉察的失真.此外,隐蔽图像中嵌入数据的提取与原始图像无关.同时,采用伪随机机制的图像遍历顺序,提高了信息的隐蔽性.     

差异聚类和误差纹理合成的生成式信息隐藏

目的 搜索式无载体信息隐藏容量小、搜索量大,涉及大量载体密集传输;纹理构造式隐藏只能生成简单非自然纹理;纹理合成式隐藏存在固定映射以及编码、非编码小块的明显区别特征,且未考虑样本小块差异度和遭受攻击时的类别提取错误,抵抗攻击能力十分有限。针对以上问题,提出一种差异聚类和误差纹理合成的生成式信息隐藏。方法 在嵌入时,通过差异均值聚类获取编码样本小块,结合多重映射将代表秘密信息的编码样本小块随机放置在空白图像上,按最小误差优先拼接策略生成含密纹理。在提取时,通过密钥截取样本小块,寻找最接近编码样本小块,并结合秘密信息MD5（message-digest algorithm 5）值和随机坐标来恢复秘密信息。结果 所提方法与MD5值和密钥紧密绑定,密钥参数、MD5值以及样例图的改变都将导致秘密信息的提取误码率趋近于0.5。同现有方法相比,结合最小误差优先拼接策略,所提方法的像素累计差异更小,含密纹理视觉质量较好且对密钥极度敏感,以实验样本为例,当遭受质量因子为5070的JPEG压缩和5% 15%的椒盐噪声攻击时,秘密信息可完整提取。即使遭受25% 40%的椒盐噪声攻击,提取误码率低于7%。结论 所提方法避免了固定映射和编码、非编码小块的区别特征,含密掩体视觉质量较好且具有较强的抗攻击能力。