Reversible Semi-Fragile Watermarking Technique for Integrity Control of Relational Database

Reversible watermarking schemes for relational database are usually classified into two groups: robust schemes and fragile schemes. The main limitation of existing reversible fragile methods is that they cannot differentiate between legal and malicious modifications. In this paper, we introduce a novel lossless semi-fragile scheme based on prediction-error expansion for content protection of relational database. In the proposed method, all attributes in a database relation are first classified according to their sensitivity to legitimate updates. Then, the watermark is embedded by expanding the prediction error of the two least significant digits of securely selected attributes. At watermark extraction, the proposed method has the ability to fully restore the original data while detecting and localizing tampering. The applicability of our method is demonstrated theoretically and experimentally.

Improving Video Watermarking through Galois Field GF(2^(4)) Multiplication Tables with Diverse Irreducible Polynomials and Adaptive Techniques

Video watermarking plays a crucial role in protecting intellectual property rights and ensuring content authenticity.This study delves into the integration of Galois Field(GF)multiplication tables,especially GF(2^(4)),and their interaction with distinct irreducible polynomials.The primary aim is to enhance watermarking techniques for achieving imperceptibility,robustness,and efficient execution time.The research employs scene selection and adaptive thresholding techniques to streamline the watermarking process.Scene selection is used strategically to embed watermarks in the most vital frames of the video,while adaptive thresholding methods ensure that the watermarking process adheres to imperceptibility criteria,maintaining the video's visual quality.Concurrently,careful consideration is given to execution time,crucial in real-world scenarios,to balance efficiency and efficacy.The Peak Signal-to-Noise Ratio(PSNR)serves as a pivotal metric to gauge the watermark's imperceptibility and video quality.The study explores various irreducible polynomials,navigating the trade-offs between computational efficiency and watermark imperceptibility.In parallel,the study pays careful attention to the execution time,a paramount consideration in real-world scenarios,to strike a balance between efficiency and efficacy.This comprehensive analysis provides valuable insights into the interplay of GF multiplication tables,diverse irreducible polynomials,scene selection,adaptive thresholding,imperceptibility,and execution time.The evaluation of the proposed algorithm's robustness was conducted using PSNR and NC metrics,and it was subjected to assessment under the impact of five distinct attack scenarios.These findings contribute to the development of watermarking strategies that balance imperceptibility,robustness,and processing efficiency,enhancing the field's practicality and effectiveness.

A multiple watermarks algorithm for image content authentication

A novel multiple watermarks cooperative authentication algorithm was presented for image contents authentication.This algorithm is able to extract multiple features from the image wavelet domain,which is based on that the t watermarks are generated.Moreover,a new watermark embedding method,using the space geometric model,was proposed,in order to effectively tackle with the mutual influences problem among t watermarks.Specifically,the incidental tampering location,the classification of intentional content tampering and the incidental modification can be achieved via mutual cooperation of the t watermarks.Both the theoretical analysis and simulations results validate the feasibility and efficacy of the proposed algorithm.

Blind multiple watermarking algorithm for audio

To make digital watermarking accomplish several goals, a new method for simultaneously embedding multiple watermarks into the same audio signal is proposed. First, the original audio signal is segmented into frames of appointed lengths and all the element watermarks are encoded to achieve a mixed watermark. Then, the binary bits in the mixed watermark are embedded into the audio frames with the echo hiding technique. The watermark extraction can be performed without an original audio signal. Furthermore, in order to enhance the extraction accuracy and the robustness of the proposed algorithm against common signal manipulations, the autocorrelafion of the power cepstrum is utilized to estimate the echo delays in the watermarked audio frames to extract the mixed watermark and the corresponding decoding method is applied to achieve the element watermarks. Computer simulation results indicate that the proposed scheme has great robustness against common signal manipulations of Mp3 compressing, re-sampling, re-quantizing, low-pass filtering and white noise addition.

Semi-Fragile Audio Watermarking Algorithm in DWT Domain

A novel semi-fragile audio watermarking algorithm in DWT domain is proposed in this paper.This method transforms the original audio into 3-layer wavelet domain and divides approximation wavelet coefficients into many groups.Through computing mean quantization of per group,this algorithm embeds the watermark signal into the average value of the wavelet coefficients.Experimental results show that our semi-fragile audio watermarking algorithm is not only inaudible and robust against various common images processing,but also fragile to malicious modification.Especially,it can detect the tampered regions effectively.

SEMI-FRAGILE WATERMARKING ALGORITHM FOR IMAGE TAMPERS LOCALIZATION AND RECOVERY

Two watermarks are embedded into the original image. One is the authentication watermark generated by secret key, which is embedded into the sub-LSB （Least Significant Bit） of the original image for tamper localization; the other is the recovery watermark for tamper recovering. The original image is divided into 8 x 8 blocks and each block is transformed by Discrete Cosine Transform （DCT）. For each block, some lower frequency DCT coefficients are chosen to be quantized and binary encoded so as to gain the recovery watermark of each block, and the recovery watermark is embedded into the LSB of another block by chaos encryption and authentication chain technology. After the two watermarks being detected, the location of any minute changes in image can be detected, and the tampered image data can be recovered effectively. In the paper, the number of coefficients and their bit lengths are carefully chosen in order to satisfy with the payload of each block and gain the capability of self-recovering. The proposed algorithm can well resist against possible forged attacks. Experimental results show that the watermark generated by the proposed algorithm is sensitive to tiny changes in images, and it has higher accuracy of tamper localization and good capability of the tamper recovery.

A new semi-fragile watermarking algorithm for image authentication

This paper presents a new semi-fragile watermarking algorithm for image authentication which extracts image features from the low frequency domain to generate two watermarks: one for classifying of the intentional content modification and the other for indicating the modified location. The algorithm provides an effective mechanism for image authentication. The watermark generation and watermark embedment are disposed in the image itself, and the received image authentication needs no information about the original image or watermark. The algorithm increases watermark security and prevents forged watermark. Experimental results show that the algorithm can identify intentional content modification and incidental tampering, and also indicate the location where a modification takes place.

Multiple Image Watermarking with Discrete Cosine Transform

Multiple image watermarking is an advanced concept of singular watermarking techniques. The existing singular digital image watermarking techniques cannot obtain all the design goals, such as imperceptibility, robustness, security, and capacity simultaneously with perfection. Hence, the multiple image watermarking technique is designed that embeds several watermarks into the same host image for conveying multiple information. This paper proposed a multiple image watermarking technique with Discrete Cosine Transform (DCT) for ensuring the low computational time for embedding, encryption, decryption as well as extraction of the watermark images. Here, DCT is used to ensure the visual quality of the host image, and a random binary matrix is used to improve the security of the digital image. We have given a basic framework for multiple image watermarking. Our experimental results show satisfactory performance.

A Dynamic Multiple Watermarking Algorithm Based on DWT and HVS

In this paper, a dynamic robust multiple watermarking algorithm is proposed based on Discrete Wavelet Transform (DWT) and Human Visual System (HVS). Watermark image is transformed by Arnold transform. Original image is divided into blocks with 8 by 8 and each block is transformed by DWT. By adopting the Just Noticeable Difference (JND) of HVS and changing low frequency coefficients, binary string message can be embedded into the decomposed original image. Watermark can be extracted blindly. Experimental results have shown that the proposed watermarking has robust against many attacks such as JPEG compressing, cropping, additive noise, line removal, median filter and related attacks with sinStirMark.

A multiple copyright identification watermarking algorithm based on code division multiple access

A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access （CDMA） system. Multiple watermarks are embedded into digital images in the wavelet transform domain. Each of the watermarks is embedded and extracted independently without impacts to each other. Multiple watermarks are convolution encoded and block interleaved, and the orthogonal Gold sequences are used to spread spectrum of the copyright messages. CDMA encoded water-mark messages are embedded into the wavelet sub-bands excluding the wavelet HH1 sub-bands. The embedment amplitude is decided by Watson＇ s perceptual model of wavelet transform domain, and the embedmeut position in the selected wavelet sub-bands is decided randomly by a pseudo-random noise （PN） sequence. As a blind watermm＇king algorithm, watermarks are extracted without original image. The watermarking capacity of proposed algorithm is also discussed. When two watermarks are embedded in an image at the same time, the capacity is larger than the capacity when a single watermark is embedded, and is smaller than the sum of the capacity of two separately embedded watermarks. Experimental results show that the proposed algorithm improves the detection bits error rate （BER） observably, and the multiple watermarks have a preferable robustness and invisibility.

基于多通道的彩色图像多重水印算法

针对多重水印技术如何确定最优的嵌入区域,以实现多个水印之间的权衡问题,提出一种基于多通道嵌入的彩色图像多重水印算法。当嵌入水印时,选择在彩色图像R、G、B 3个通道嵌入不同的水印图像,目的是嵌入更多的水印信息。通过提升小波变换(LWT)和非下采样剪切波变换(NSST)提取宿主图像每个通道中的方向性特征,确定水印的嵌入位置,以提高对常规攻击和几何攻击的鲁棒性。通过将加密的水印有效信息嵌入到具有良好稳定性的奇异值矩阵中,保证水印的提取效果。实验结果表明,嵌入水印后的图像峰值信噪比(PSNR)在43 dB以上,所提算法具备良好的不可见性,对嵌入水印后的图像进行高强度的旋转、滤波、剪切等攻击,提取水印的归一化系数(NC)值在0.95以上,其中,滤波攻击对应的NC值可以达到0.99以上,水印信息提取完整、清晰可辨,表现出较强的鲁棒性。同时,该算法可以1次嵌入3个水印图像,具有更高的嵌入容量。因此,与现有的多重水印算法相比,该算法的不可见性、鲁棒性和嵌入容量均有较大的提升。

An H.264/AVC Video Watermarking Scheme in VLC Domain for Content Authentication

A semi-fragile content authentication algorithm is proposed for low bit-rate H.264/AVC video in VLC domain. Utilizing the intra prediction mode and coded block pattern in VLC domain, the proposed algorithm chooses those macro-blocks from which the signature is extracted and constructs content signature at macro-block level according to the relationship among the energies of quantized low-frequency coefficients of sub-macroblocks. The signature is embedded by modifying the trailing coefficients. The experimental results show that the proposed algorithm performs well in visual quality impact and keep the bit-rate basically unchanged. In addition, the algorithm can embed signatures into I, P, B slices simultaneously and remarkably enhances the watermark capacity. By verifying the extracted signature, the algorithm can detect and locate video tampering efficiently.

Reversible Digital Image Watermarking Scheme Using Bit Replacement and Majority Algorithm Technique

The current paper presents a new digital watermarking method through bit replacement technology, which stores mul-tiple copies of the same data that is to be hidden in a scrambled form in the cover image. In this paper an indigenous approach is described for recovering the data from the damaged copies of the data under attack by applying a majority algorithm to find the closest twin of the embedded information. A new type of non-oblivious detection method is also proposed. The improvement in performance is supported through experimental results which show much enhancement in the visual and statistical invisibility of hidden data.

云计算环境下的QR码双重加密复合数字水印算法

为了确保上传到“云”端环境下的数字产品的隐蔽性和安全性,在逐渐向“云”端转移的快速响应(Quick Response, QR)码的理论基础上研究并提出了一种QR码双重加密复合数字水印算法,防止QR码“云”端丢失的可能性。对“云”水印图像进行QR码编码生成QR码水印图像,确保水印信息的安全性,再对QR码水印信息实施加密置乱;对“云”上载体Lena图像进行非下采样轮廓波变换(Non-subsampled Contourlet Transform, NSCT),选择储存信息更多的低频部分进行离散小波变换(Discrete Wavelet Transform, DWT),对图像抵抗力较强的低频图像进行奇异值分解(Singular Value Decomposition, SVD),在分解的奇异值中加权加密的QR码水印。通过对算法进行实验验证,该算法在视觉效果较好的前提下,考虑实用性,将复合算法和加密相结合,提高了算法的抵抗力,尤其是旋转攻击和JPEG压缩攻击。

基于混沌加密的QR码彩色图像复合水印算法

本研究提出了一种基于NSCT-DWT-SVD复合的QR码混沌加密彩色图像水印算法。首先将“飞行学院”四字组成的水印图像通过编码器进行QR编码生成QR码水印信息,再对水印进行Logistic混沌映射加密,将RGB颜色模型的原载体图像转换成YUV颜色模型图像,对转换后的模型Y分量进行提取,将其进行NSCT生成低频分量,随后进行小波变换及SVD奇异值分解获得奇异值,最后将加密的QR码通过加性原理叠加到分解后的奇异值上。通过实验证明,该算法得到的峰值PSNR为52.15dB,保证了嵌入水印的信息量及隐蔽性,对椒盐噪音、JPEG压缩攻击NC值都为1,尤其是由于加入NSCT保证了图像的平移不变性,SVD更是提高了算法抵抗旋转攻击的能力。

传承与衍生:庐州木版水印“非遗”技艺的可持续发展研究

庐州木版水印作为安徽省省级非物质文化遗产项目,以丰富的艺术内涵、悠久的工艺传统、精湛的技术水准、独特的视觉效果而著称。作为雕版印刷的一种特殊形式,木版水印中的饾版套色技术突破了单色雕版的限制,创造性地实现了多彩叠加、分色套印。刻印精绝,用色雅丽,与原画难分伯仲,为赏家所称颂。当前,合肥正在加快打造具有国际影响力的创新名城和群众精神文明生活更加丰富的文化之城。“非遗”文化带来的特殊魅力愈发受到珍视,在工业印刷、电子视觉艺术蓬勃发展的今天,传承、保护古老的手工印刷技术尤显意义重大。在赓续传统的同时,通过创新衍生,结合本土科技传统和产业,将木版水印工艺运用在新媒材的装饰之上,庶几能够成为这一古老技艺可持续发展的新路径。

基于BEMD与DCT的彩色图像多重水印鲁棒算法

为解决现有彩色图像水印算法容错性低及宿主图像与水印图像在嵌入时尺寸匹配问题,并提高算法抵御各种攻击的鲁棒性,提出一种基于二维经验模态分解(BEMD)和离散余弦变换(DCT)的彩色图像多重水印鲁棒算法。使用Arnold变换对3幅二值水印图像进行置乱,分别对彩色宿主图像的三通道进行BEMD,得到各通道的内蕴模态函数(IMF)和余量信息,选择各通道的第1个IMF(记作IMF_(1))作为水印嵌入层,对每个通道的IMF_(1)分割成不重叠子块后进行DCT;再将置乱后的二值水印图像依次重复嵌入在各通道子块经过之字形(Zigzag)扫描后的中频系数中,使用逆Zigzag扫描和逆DCT得到各通道嵌入水印信息后的IMF_(1),并与每个通道其余的IMF及余量重建得到嵌入水印后的彩色图像。水印提取为嵌入过程的逆过程,算法可以实现彩色图像嵌入水印的盲提取。在水印提取过程中对重复嵌入提取到的水印图像使用投票策略,增强了算法的容错性。大量实验结果表明:嵌入水印后的图像峰值信噪比(PSNR)在34 dB以上,水印信息具有较高的不可见性;对嵌入多重水印后的宿主图像进行大尺寸剪切、椒盐噪声等攻击实验,提取到的水印图像与原始图像的归一化系数均在0.96以上,且可达到1,水印信息提取完整清晰可辨。与现有大量彩色图像水印算法相比,所提算法具有较强抵御各种攻击的能力,同时嵌入水印后图像具有较高的不可见性。

Image Authentication Based on Digital Signatureand Semi-Fragile Watermarking

This paper proposes an authentication scheme for JPEG images based on digital signature and semi-fragile watermarking. It can detect and locate malicious manipulations made to the image, and verify the ownership of the image at the same time. The algorithm uses the invariance of the order relationship between two DCT coefficients before and after JPEG compression to embed image content dependent watermark, therefore the watermark can survive the JPEG lossy compression. Since the scheme is based on the security of the cryptographic hash function and public key algorithm, it is believed to be secure to the extent that cryptography is believed to be. Theoretical analysis and experimental results show that the proposed scheme has the desired property and good performance for image authentication.

面向水印嵌入与提取的广播电视信号检测技术

为维护广播内容的完整性与合法性,研究广播电视信号检测中的水印嵌入与提取技术。介绍数字水印的概念,探讨在广播电视信号中嵌入水印的过程,特别是加速稳健特征(Speeded Up Robust Features,SURF)算法的应用,阐述水印提取与检测方法,以确保广播内容的完整性。通过功能分析,展示该技术在广播电视行业中对未经授权的广告插播检测和信号篡改检测的关键作用。

基于时隙的多重冗余流指纹模型

随着互联网的日益广泛应用,各种网络安全问题频频暴露,以“打补丁”形式为主的安全增强模式难以有效防范日益增长的安全风险,网络安全领域研究者认为未来互联网体系架构应当将安全作为一种基本属性,实现网络架构对安全的内生支持。为了支持内生安全的数据可信,在流水印/流指纹机制的研究基础之上,设计实现了一种基于时隙的多重冗余流指纹模型。该模型使用3个时隙间隔,通过对指定时隙内的数据包进行延迟等操作,可在相邻比特操作不产生冲突的情况下实现指纹嵌入,并且引入冗余编码来提高指纹健壮性,同时考虑到网络中抖动或攻击者的恶意扰乱等行为,将延迟干扰、垃圾数据包干扰以及丢包干扰对模型的影响进行了理论分析,结果表明在给定网络流中数据的包分布时,随着冗余位的增加,指纹模型的鲁棒性明显提高。为了减少时间和空间消耗,提高数据包操作的效率和精度,基于内核设计和实现流指纹原型系统,并对其效率和鲁棒性进行评估,实验表明该模型具有很高的鲁棒性。最后,展示了所提模型的应用场景,基于该流指纹功能模型,能有效检测中间人攻击,预防网络身份欺骗。