优美图随机嵌入路径耦合像素优化的图像隐写

目的为了解决当前图像隐写方案不可感知能力差、秘密信息嵌入路径随机性较低、难以抵御盲隐写攻击,以及隐写容量小等问题。方法提出优美图随机嵌入路径耦合像素优化控制的图像无损隐写术。基于HIWT机制将载体图像转换为频域整数系数,实现无损隐写。定义图像直方图修改规则,构造隐藏信息长度估算模型,确定图像分块的频域表示,增强该算法的可靠性。引入LSB替代,设计像素区间控制机制,缩小密文与载体之间的嵌入误差。再嵌入图论,构建优美图,获取随机矩阵,确定秘密信息自适应随机嵌入路径,增强隐写的不可感知性能。借助逆向HIWT获取隐写图像。结果与当前隐写方案相比,文中隐写术具备更强的不可感知性,有效降低了阶梯效应,且隐写容量更高,提取图像无失真。结论文中算法可对图像进行安全无损隐藏,有效保护图像可靠传输。     

基于DD-DT CWT和SIFT的体数据数字水印算法

为了确保三维体数据数字模型信息在网络传输过程中的安全性、完整性,对体数据数字水印算法进行研究。提出基于双密度双树复小波变换的体数据数字水印嵌入算法,算法提高了水印的嵌入容量,在兼顾水印不可见性的同时提高了水印抵抗压缩、噪声等攻击的能力;提出基于尺度不变特征变换的体数据数字水印提取算法,实现了水印嵌入和提取时的同步性,提高了水印抵抗旋转、缩放等几何攻击的能力。实验证明:算法不可见性好,实现速度快,在盲检测下能够抵抗压缩、滤波、噪声、平移、旋转、缩放、剪切等攻击,具有较好的鲁棒性。     

基于混沌系统与提升小波的抗剪切攻击的彩色图像盲水印算法

研究了混沌序列、提升小波在彩色图像盲水印中的应用,给出一种新的基于混沌序列和提升小波的抗剪切变换攻击的彩色图像盲水印算法。算法同时采用两种不同的混沌序列,提高了算法的安全性;根据HVS特性使中低频使用不同的算法自适应地嵌入水印,使算法有了很好的隐藏效果;使用提升小波变换提高了算法的效率;对受严重攻击后提取出的水印进行优化处理,使算法有了很好的鲁棒性。实验证明该算法具有较高的效率、较好的隐藏效果、很好的安全性和鲁棒性,尤其在抗剪切攻击方面格外显著。     

基于DCT 的三维网格模型数字水印算法

基于离散余弦变换(DCT)技术和扩频通信技术提出三维模型稳健水印嵌入算法. 算法将原始的一维二值水印序列利用扩频通信技术生成可以直接嵌入的水印信息;利用主成分分析(PCA)方法,将原始模型变换到仿射(旋转、 平移和均匀缩放)不变空间中,选取模型顶点到其中心距离作为水印嵌入单元,基于双极性量化嵌入单元离散余弦变换系数的方法嵌入水印并实现水印的盲提取. 该算法嵌入的水印信息具有不可见性,能够抵抗模型的旋转、平移、均匀缩放等常见攻击. 仿真实验验证了算法的有效性.     

用多重菲涅耳衍射变换实现盲信息隐藏

提出了一种新的基于多重菲涅耳衍射变换和像素替代的盲信息隐藏算法.需隐藏的图像经多重菲涅耳衍射变换为一密文复矩阵,然后将其实部和虚部分别嵌入到原始宿主图像中,同时将此已嵌入信息的原像素值用其近邻的未嵌入信息的像素均值来替代,从而实现盲信息隐藏.数值仿真计算结果表明:该隐藏算法对JPEG有损压缩、图像剪切,噪声污染、重采样攻击和亮度、对比度、直方图、灰度曲线调整等具有一定的抵抗能力;由于采用一系列加密密钥(光波长、透镜焦距,多个衍射距离等),只有当所有密钥都正确时,才能解密恢复所隐藏的信息,所以该算法具有较强的鲁棒性和很高的安全性.     

基于网点形状的半色调全息防伪算法研究

目的研究印刷条件下基于网点形状的半色调全息防伪算法,该算法能够无失真地提取嵌入的防伪信息。方法首先对二值图像信息进行全息加密,然后对拼接的全息数据进行二值化,再把全息二值数据作为选择网点形状的判断条件,把数字图像生成半色调图像。提取防伪信息时利用全息数据的全局特性,只需任意裁切大于32×32网点大小半色调图像块,就能解密出网点携带的防伪信息。结果提取的防伪信息与嵌入的防伪信息的相似度能够达到100%;半色调图像经过鲁棒性攻击,相似度能够达到90%以上。结论该算法能够无损失地提取防伪信息,有一定的鲁棒性及安全性。     

基于IWT-SVD和BRISK的鲁棒图像水印算法

目的 针对数字图像水印中传统奇异值分解算法存在的提取水印对角线失真和目前的特征点匹配算法速度慢引起抗组合几何攻击性能弱问题,提出基于IWT-SVD和BRISK的鲁棒图像水印算法。方法 该方案是将Logistics混沌映射置乱的水印嵌入宿主图像IWT变换后进行SVD分解的矩阵中,然后运用BRISK算法完成失真图像的几何校正,最后根据提取的水印图像特性,用邻域平均法进行对角线元素修正。结果 嵌入水印后PSNR高于42 dB,在各种常规信号处理和组合几何攻击下,NC平均值在0.95以上,提取出的水印对角线失真问题得到明显改善。结论 实验结果表明,该方案能提高图像特征点的匹配速度,性能得到增强,水印不可见性较好,进一步提升了图像的鲁棒性。     

基于DCT域的数字盲水印技术

提出一种鲁棒性较好的DCT域数字盲水印方案。该方案将汉明编码应用于二值水印图像,同时,采用混沌调制序列伪随机选取嵌入区域,提高水印算法的安全性。通过分析DCT中频特定系数关系,实现水印的盲提取。实验结果表明,该算法对于常见的图像攻击具有较好的鲁棒性,是一种有效的盲水印。     

新颖的音频信息隐藏算法

基于混沌映射和改进Patchwork算法的DWT（discrete wavelet transform）域音频信息隐藏技术,实现保密语音在音频信号中的隐藏与恢复。利用混沌序列保密性高和容易再生的特性,保证了算法的安全性;新颖的Patchwork算法,修改部分小波系数,使其统计特征产生相反方向偏移,实现保密语音码流的隐藏。混沌序列的使用与小波系数修改的隐蔽性,加强了算法的安全性;在保证隐藏量的同时,实现了隐藏信息的盲提取。实验表明,隐藏信息后载体音频SNR在50dB左右;在载体音频失真可容忍的情况下,提取的保密语音码流BER均小于0．1％,能够保证隐藏音频的听觉质量和隐藏信息的安全。     

一种基于块均值的盲检测水印算法

提出了一种新颖的盲检测水印算法.该方法是一种利用图像块的DCT系数的算术均值来隐藏水印信息的盲检测水印算法,该算法在提取水印时不需要原始公开宿主图像,并且对常见水印攻击方法JPEG攻击具有良好的稳健性.     

Improved security in the genetic algorithm-based image steganography scheme using Hilbert space-filling curve

This paper presents the security analysis of a recently proposed data hiding scheme by Kanan and Nazeri [A novel image steganography scheme with high embedding capacity and tunable visual image quality based on a genetic algorithm. Expert Syst Appl. 2014;41(14):6123–6130]. Security of the scheme depends upon a secret key\chromosome constructed using a genetic algorithm. The key specifies offsets and patterns for data embedding. By performing the key-sensitivity analysis and exploiting image pixel correlation, it is shown in the present paper that the secret data can be easily revealed. Simulation results demonstrate that just 11 bits out of the 27-bit secret key are sufficient to reveal the data. To overcome the problem, an improvement is suggested in the data embedding pattern that demonstrates high data security. Bitwise analysis of the secret key used in the modified approach exhibits high sensitivity to change in the key.     

一种非对称鲁棒性盲水印算法

针对数字图像版权保护，提出一种非对称鲁棒性盲数字水印方法。通过将水印嵌入到最少受图像改变影响的子空间，使嵌入水印具有鲁棒性，且通过对特征子空间的选取限制，使算法具有较高的检测概率和安全性以及较低的虚警概率。同时，水印嵌入矩阵与提取矩阵不同，它可公开除密钥外的所有其它的信息，而且能实现水印盲提取。实验结果证明了该算法的鲁棒性。     

An Image Steganography Algorithm Based on Quantization Index Modulation Resisting Scaling Attacks and Statistical Detection

In view of the fact that the current adaptive steganography algorithms are difficult to resist scaling attacks and that a method resisting scaling attack is only for the nearest neighbor interpolation method, this paper proposes an image steganography algorithm based on quantization index modulation resisting both scaling attacks and statistical detection. For the spatial image, this paper uses the watermarking algorithm based on quantization index modulation to extract the embedded domain. Then construct the embedding distortion function of the new embedded domain based on S-UNIWARD steganography, and use the minimum distortion coding to realize the embedding of the secret messages. Finally, according to the embedding modification amplitude of secret messages in the new embedded domain, the quantization index modulation algorithm is applied to realize the final embedding of secret messages in the original embedded domain. The experimental results show that the algorithm proposed is robust to the three common interpolation attacks including the nearest neighbor interpolation, the bilinear interpolation and the bicubic interpolation. And the average correct extraction rate of embedded messages increases from 50% to over 93% after 0.5 times-fold scaling attack using the bicubic interpolation method, compared with the classical steganography algorithm S-UNIWARD. Also the algorithm proposed has higher detection resistance than the original watermarking algorithm based on quantization index modulation.     

Varying index varying bits substitution algorithm for the implementation of VLSB steganography

Variable least significant bits (VLSB) steganography is a pretty powerful and secure technique for data hiding in cover images, having variable data hiding capacity, signal-to-noise ratio, peak signal-to-noise ratio, and mean square error (MSE). This study presents a new algorithm for the implementation of VLSB steganography named varying index varying bits substitution (VIVBS). The VIVBS algorithm is a very secure, high capacity, flexible, and statistically unpredictable mechanism to conceal information in cover images. The method uses a secret stego-key comprising a reference point, and variation of the number of bits to be hidden with varying indices of pixels in the cover image. The secret key adds an extra feature of security to steganography, making it much immune to steganalysis. The VIVBS algorithm is capable of providing variable data hiding capacity and variable key size which can be changed by changing the range of least significant bits used. A data hiding capacity of 43.75% with a negligible MSE 14.67 dB has been achieved using the VIVBS algorithm. For larger data hiding capacity, the MSE and distortion increases significantly which make the existence of information predictable but the key size also increases significantly, making the retrieval of hidden information difficult for the unauthorized person.     

DWT-based blind and robust watermarking using SPIHT algorithm with applications in tele-medicine

Malicious manipulation of digital images cannot be ignored in certain critical application like tele-medicine, where medical records of the patients (mostly in the form of diagnostic images of brain, chest, heart, lungs, etc.) need to be securely transmitted over the internet for various life-saving consultation and treatments. Watermarking is used to protect such documents from being manipulated and helps detect the authenticity of the image received. A robust and blind image watermarking technique based on discrete wavelet transform is proposed in this paper. For embedding purpose, suitable coefficients are found out using the Set Partitioning in Hierarchical Trees algorithm. Level of security is further enhanced by scrambling the watermark using Arnold transform and by making the set of embedding locations random using a secret key. Noise Visibility Function is used to compute the minimum allowable distortion for each coefficient before embedding to achieve better image fidelity. Experimental results show that the proposed scheme is robust against certain standard image processing attacks and outperforms the prior existing similar types of watermarking schemes.     

A method of data hiding in audio signal

Information hiding and secret communication is one of the most interesting and fascinating domains. This hiding method exploits some features of audio signals to be able to hide data from perception robustly. Every year researchers introduce their work and discuss how to make these techniques more and more robust against different types of attacks. In this article, we present an improved audio steganography approach that reduces distortion of the stego audio. Using the proposed algorithm, secret information is strongly protected from hackers and sent to its destination in a safe manner.     

基于QR码与混沌加密的Contourlet域彩色图像盲水印算法

目的针对现行数字水印算法中抗几何攻击能力弱以及嵌入水印信息容量差的问题,提出一种Contourlet变换下QR码与混沌加密相结合的彩色图像水印算法。方法采用QR码作为水印图像,利用Logistic混沌序列对其进行加密,再将加密的水印图像嵌入到二级Contourlet变换的低通子带中,利用系数间的大小关系,修改系数完成水印嵌入与提取。结果通过实验结果可知,水印的嵌入对载体图像影响较小,PSNR值高达42.764,经过旋转、剪切及常规攻击后,提取出的水印均可正确解码。结论该算法具有良好的安全性、不可见性,对于各类攻击具有较优的鲁棒性。水印信息容量高于普通图像,水印提取方式为盲提取,能够更好地满足各类数字作品版权保护的实际需要。     

Reversible Data Hiding in Encrypted Images Based on Prediction and Adaptive Classification Scrambling

Reversible data hiding in encrypted images (RDH-EI) technology is widely used in cloud storage for image privacy protection. In order to improve the embedding capacity of the RDH-EI algorithm and the security of the encrypted images, we proposed a reversible data hiding algorithm for encrypted images based on prediction and adaptive classification scrambling. First, the prediction error image is obtained by a novel prediction method before encryption. Then, the image pixel values are divided into two categories by the threshold range, which is selected adaptively according to the image content. Multiple high-significant bits of pixels within the threshold range are used for embedding data and pixel values outside the threshold range remain unchanged. The optimal threshold selected adaptively ensures the maximum embedding capacity of the algorithm. Moreover, the security of encrypted images can be improved by the combination of XOR encryption and classification scrambling encryption since the embedded data is independent of the pixel position. Experiment results demonstrate that the proposed method has higher embedding capacity compared with the current state-ofthe-art methods for images with different texture complexity.     

An Effective Steganalysis Algorithm for Histogram-Shifting Based Reversible Data Hiding

To measure the security for hot searched reversible data hiding (RDH) technique, especially for the common-used histogram-shifting based RDH (denoted as HS-RDH), several steganalysis schemes are designed to detect whether some secret data has been hidden in a normal-looking image. However, conventional steganalysis schemes focused on the previous RDH algorithms, i.e., some early spatial/pixel domain-based histogram-shifting (HS) schemes, which might cause great changes in statistical characteristics and thus be easy to be detected. For recent improved methods, such as some adaptive prediction error (PE) based embedding schemes, those conventional schemes might be invalid, since those adaptive embedding mechanism would effectively reduce the embedding trace and thus increase the difficulty of steganalysis. Therefore, a novel steganalysis method is proposed in this paper to detect recent adaptive RDH schemes and provide a more effective detection tool for RDH. The contributions of this paper could be summarized as follows. (1) By analyzing the characteristics for those adaptive HS-RDH, an effective “flat ground” based detection method is designed to fast identify whether the given image is used to hide secret data; (2) According to the empirical statistical model, double check mechanism is provided to improve the detection accuracy; (3) In addition, to further improve detection ability, some detailed information for secret data, i.e., its content and embedding location are further estimated. Compared with conventional steganalysis methods, experimental results indicate that our proposed algorithm could achieve a better detection accuracy and meanwhile acquire more detailed information on secret data.