W(L)矩阵及信息隐藏方法

给出了一个W^（L）矩阵，及相关的性质，并在此基础上，提出了一种新的数据嵌入方法，可在（2L＋1）bit宿主信息中，嵌入2L bit数据而最多只需要修改L bit宿主信息。这种方法，有较大的数据嵌入率，且对宿主信息的改变也较少，比较适用于大信息量，特别是流媒体数据的隐藏及隐秘传输。     

基于拓展广义整数变换的无损信息隐藏方法

为使用于无损信息隐藏的广义整数变换更具普遍意义并提高数据嵌入容量,该文在对广义整数变换进行拓展的基础上提出一种图像无损信息隐藏新方法。该方法通过对广义整数变换引入可变参数m进行拓展,可在n个像素点组成的图像块中嵌入m(n-1) bit数据,m＞1时提高了数据嵌入容量,方法还采用一种新的数据嵌入策略提高了隐藏图像质量。与现有整数变换算法相比,该文算法在数据嵌入容量和隐藏图像质量上有一定的提升。该方法可用于对图像质量要求较高的军事通信、医学保健和法律论证等领域,在提取嵌入的机密信息后,原宿主图像可无失真恢复。     

基于嵌入矩阵的二值图像隐藏方法

描述了一种基于嵌入矩阵的二值图像信息隐藏方法,该方法将图像交叉分块后,计算各子块的可修改分值,根据可修改分值的大小选取子块的中心像素作为数据嵌入的位置;数据嵌入时,使用基于嵌入矩阵的信息隐藏方法,在嵌入同等数据量的同时,可有效地减少对原图像数据的修改.     

一种基于JPEG压缩图像的信息隐藏方法

描述了一种基于JPEG图像的信息隐藏新方法.该方法用I/I矩阵在8×8子块DCT域的2m比特中低频量化系数的最低位中,最多修改[m/2]比特数据,即可嵌入m比特信息,有较高的数据嵌入率及较好隐蔽性.该方法已在计算机上进行了模拟实验,并获得了较好的结果.     

一种新的数据隐藏方法

本文提出一种新的数据隐藏方法,对于给定长为n比特的可修改宿主数据流,至多修改1比特宿主数据,可嵌入log₂(n+1)比特的数据.嵌入/提取矩阵 H ,还可作为密钥,使得嵌入数据具有较好的安全性.该方法已在微机上进行了模拟,获得了预期的结果.     

基于BMP文件信息隐藏技术的探讨

信息隐藏技术的出现和发展,为信息安全的研究扩展了一个新的领域.编程时采用最低有效位算法(LSB算法)将秘密信息嵌入作为栽体的24位真彩色BMP图像中,并对算法进行了两点改进:将控制信息也当作秘密信息嵌入到BMP文件的图像数据区;嵌入信息时,与载体信息进行了一步运算.     

改进的基于快速相关矢量量化的高效信息隐藏方法

为了改善信息隐藏后的图像质量,减少失真,并提高嵌入信息的容量,本文提出了一种新的改进的基于快速相关矢量量化（MFCVQ,modified fast correlation VQ）的信息隐藏方法。由于图像本身的相关性,快速相关矢量量化利用了当前索引的相邻矢量进行替代编码,计算编码时使用的相邻矢量所产生的失真与事先设定的门限做比较,当失真小于门限时可以进行替代编码,一步完成了编码和嵌入信息;当失真大于门限时不能进行替代编码,从而控制了当前索引的嵌入和最后生成图像的视觉质量。同时,增加了相邻矢量的数目,提高了嵌入信息的容量。实验结果表明改进后的算法能够显著改善图像失真,在门限为18时对不同复杂程度的图像其PSNR分别提高了0.018dB-2.125dB,并且有效地提高了嵌入容量,进而大幅度的提高了嵌入效率。改进算法的嵌入效率达到了Yang算法的1.967-4.683倍。      

基于安全通信的信息隐藏技术研究

针对传统信息隐藏技术安全程度低的问题,提出一种基于安全通信的信息隐藏技术。通过实时对网络中流经的数据进行分析,确定包含隐藏信息的数据,采用信息嵌入算法将隐秘信息同伪随机序列加密处理,在此基础上,生成网络信息隐藏控制信道,将秘密信息通过此信道发送,以保证隐藏信息的安全性,以此实现信息的隐藏。仿真结果表明,该隐藏技术比传统隐藏技术的安全程度高,大大减少了信息被窃取的现象,推动了该领域的研究发展,具有一定的实际应用意义。     

图像抛物线插值空间大容量可逆信息隐藏算法

针对可逆信息隐藏算法嵌入容量小、通用性差、运行效率低等问题,提出以插值图像为载体的大容量可逆信息隐藏方法,设计了一种类线性图像插值方法,通过实验数据分析给出了理想插值图像的期望插值,将载体图像两相邻像素值看作抛物线的根,构造一元二次方程,利用方程性质,建立以抛物线最值为参考点、以两根均值为期望插值的模型,根据差值区间确定出可嵌入位置和位数,再由区间调整因子和秘密信息共同确定出最终插值,设计了两种可逆隐藏方案,均无附加信息、无数据溢出,平均嵌入率接近4bit/pixel,载密图像有较高质量,通过与5种优秀算法的实验比较,表明算法在嵌入容量、隐蔽性、运行效率等方面相对比较算法有一定优势.     

图像及音频信号中隐蔽嵌入信息存在性的统计检验

作为对信息隐藏攻击和反攻击研究的一个环节,正确判断数字图像和音频信号中是否存在隐蔽嵌入信息具有重要意义。该文提出一种统计分析方法,基于数据的时(空)域局部相关特性给出3个性能互补的判别准则,用来对视听觉无差异的两个样本进行检验,以辨别其中哪一个可能携带有隐蔽信息。实验结果表明,判别准确率令人满意。     

基于比特控制的快速矩阵嵌入

为了保证安全和信息传输率,隐写术期望能利用对载体的每个修改嵌入尽可能多的信息,也即提高嵌入效率。矩阵嵌入是最主要的提高嵌入效率的编码方法。Fridrich提出的基于随机线性码的矩阵嵌入方法能达到高的嵌入效率,但是计算复杂度较高。该文利用择多校验法对矩阵嵌入进行改进,首先使用控制比特对载体分组进行异或构造新载体,然后在新载体上执行矩阵嵌入,通过考察控制比特的状态可以快速生成修改量尽可能小的模式。分析和实验表明,该方法可以在嵌入效率和嵌入速度之间灵活的进行折中。与Fridrich的原始方法相比,新方法在保持嵌入效率基本不变的情况下,其计算复杂度随着控制比特数的增加以指数速度降低。与已有的快速矩阵嵌入方法比,新方法能以更快的嵌入速度达到更高的嵌入效率。     

Hybrid prediction-based pixel-value-ordering method for reversible data hiding

Pixel-value-ordering (PVO) is an effective and promising method of reversible data hiding (RDH) and has received much attention in recent years. To improve performance, a pixel-based PVO (PPVO) method was recently introduced to predict the pixels to be embedded in a pixel-wise manner instead of the block-wise manner used by PVO. However, for PPVO, the surrounding neighbors of the predicted pixels are underutilized; moreover, its embedding does not adapt to the local complexity of the image to be embedded. To overcome the shortcomings of PPVO, this paper proposes a novel PVO method based on hybrid prediction for RDH. First, the surrounding neighbors of the pixel to be predicted are fully utilized by a hybrid prediction method, which combines rhombus prediction and pixel-wise prediction. Second, a modified embedding scheme based on multiple histograms is presented for adaptive embedding. Experimental results show the superior performance of the proposed method by comparing it with state-of-the-art RDH methods.     

一种基于湿纸编码和图匹配理论的直方图保持隐写算法

该文结合隐写码、湿纸码和图匹配理论提出一种具有高嵌入效率的且可保持载体图像一阶直方图的双层嵌入隐写算法。首先构造出一条新的四进制的隐写信道,然后在该信道的LSB(Least Significant Bit)层和次LSB层分别使用二元隐写码和湿纸码嵌入秘密消息,这样即可确定出需要修改的元素,接着构造出一个图,最后使用图论中匹配算法寻找一种减小失真且保持直方图的修改方式。性能分析和实验结果表明:在嵌入相同长度秘密消息的情况下,新算法的PSNR、嵌入效率和保持一阶直方图效果均优于隐写软件Steghide。     

基于统计特征的音频中隐藏信息估计方法

该文基于信息嵌入不同位平面所引起的幅度统计分布变化,提出了一种音频中隐藏信息长度估计方法。通过该方法,不仅可以判别未知音频中是否包含隐藏信息,而且还能有效识别信息嵌入位平面和较精确地估计隐藏信息长度。该方法已在微机上进行了实验,实验结果表明,该方法识别正确率较高,隐藏信息长度估计较精确,可有效用于音频隐藏分析。     

Robust reversible image watermarking scheme based on spread spectrum

Robust reversible watermarking can provide robustness against various attacks besides the ability to recover the cover image. However, robustness and reversibility are somewhat separate in many schemes. The original cover image cannot be recovered even if the watermarked image suffers from a tiny distortion. This paper presents a new robust reversible watermarking scheme by exploring the reversibility of spread-spectrum codes. Watermark bits are embedded by a suggested adaptive spread-spectrum code. The embedding amplitude used in the algorithms is determined by quantizing the source interference of the cover. The proposed scheme is robust to various attacks. Furthermore, since the embedding amplitude is available at the receiver, the original image can be recovered losslessly when there is no attack. Even in the presence of attacks, the original cover images can still be partially recovered. Experimental results demonstrate that the proposed scheme performs well on robustness and watermarked image quality, and provide extra reversibility that resists image distortions.     

Reversible data hiding with automatic contrast enhancement using two-sided histogram expansion

Recently, reversible data hiding (RDH) has emerged into a new class of data hiding methods that enables exact retrieving of both embedded data and cover medium. In the present study, a novel automatic RDH method with contrast enhancement is proposed, in which the data is embedded through two-sided histogram expansion. Two-sided histogram shifting doubles the number of bits embedded at each iteration. Moreover, it preserves the mean brightness of the cover image and prevents it from over enhancement with less calculation. Experimental results on two sets of images show that the proposed method enhances the image contrast at an appropriate level without using a mean brightness controller during data embedding and provides higher information security compared to the existing RDH approaches.     

Study on audio information hiding method based on modified phase partition

Hiding efficiency of traditional audio information hiding methods is always low since the sentience similarity cannot be guaranteed. A new audio information hiding method is proposed in this letter which can impose the insensitivity with the audio phase for auditory and realize the information hiding through specific algorithm in order to modify local phase within the auditory perception. The algorithm is to introduce the operation of “set 1” and “set 0” for every phase vectors, then the phases must lie on the boundary of a phase area after modified. If it lies on “1” boundary, it comes by set 1 operation. If it lies on “0” boundary, it comes by set 0 operation. The results show that, compared with the legacy method, the proposed method has better auditory similarity, larger information embedding capacity and lower code error rate. As a kind of blind detect method, it fits for application scenario without channel interference.     

语音信号相空间重构中嵌人维数的选择

嵌入维是时间序列相空间重构中的基本参数。本文基于增大重构维以减少虚邻点的思想,构造了一种求合适最小嵌入维的方法。文章详细讨论了本方法的原理,给出了具体的算法构造,分析了算法性能,比较了本方法与已有同类方法的不同。用本方法,除可得到适合的最小嵌入维外,还可评估重构数据中所含的噪声强弱。并得到重构质量评价。将本方法应用于语音信号相空间重构,得到了语音信号一般情况下的嵌入维数。     

HEVC video information hiding scheme based on adaptive double-layer embedding strategy

High Efficiency Video Coding (HEVC) is well-known as an internationally popular video coding standard, and HEVC-based steganography has received increasing attention. In this paper, a new adaptive HEVC video information hiding method based on Prediction Unit (PU) partition mode and double-layer embedding strategy is proposed. Double-layer embedding is a method to complete the first-layer embedding using the mapping rules of PU partition mode, and to perform the second-layer embedding after the first-layer embedding. The cost assignment function designed in this paper can accurately evaluate the second-layer data embedding distortion. The frame position, motion properties and block size of PU are taken into consideration for the second-layer data embedding, and the syndrome-trellis codes (STCs) are used to minimize the embedding distortion. Experimental results show that the proposed adaptive double-layer embedding algorithm has better embedding efficiency and less embedding distortion in most cases.