A Hybrid Intelligent Approach for Content Authentication and Tampering Detection of Arabic Text Transmitted via Internet

In this paper, a hybrid intelligent text zero-watermarking approach has been proposed by integrating text zero-watermarking and hidden Markov model as natural language processing techniques for the content authentication and tampering detection of Arabic text contents. The proposed approach known as Second order of Alphanumeric Mechanism of Markov model and Zero-Watermarking Approach (SAMMZWA). Second level order of alphanumeric mechanism based on hidden Markov model is integrated with text zero-watermarking techniques to improve the overall performance and tampering detection accuracy of the proposed approach. The SAMMZWA approach embeds and detects the watermark logically without altering the original text document. The extracted features are used as a watermark information and integrated with digital zero-watermarking techniques. To detect eventual tampering, SAMMZWA has been implemented and validated with attacked Arabic text. Experiments were performed on four datasets of varying lengths under multiple random locations of insertion, reorder and deletion attacks. The experimental results show that our method is more sensitive for all kinds of tampering attacks with high level accuracy of tampering detection than compared methods.     

Smart-Fragile Authentication Scheme for Robust Detecting of Tampering Attacks on English Text

Content authentication, integrity verification, and tampering detection of digital content exchanged via the internet have been used to address a major concern in information and communication technology. In this paper, a text zero-watermarking approach known as Smart-Fragile Approach based on Soft Computing and Digital Watermarking (SFASCDW) is proposed for content authentication and tampering detection of English text. A first-level order of alphanumeric mechanism, based on hidden Markov model, is integrated with digital zero-watermarking techniques to improve the watermark robustness of the proposed approach. The researcher uses the first-level order and alphanumeric mechanism of Markov model as a soft computing technique to analyze English text. Moreover, he extracts the features of the interrelationship among the contexts of the text, utilizes the extracted features as watermark information, and validates it later with the studied English text to detect any tampering. SFASCDW has been implemented using PHP with VS code IDE. The robustness, effectiveness, and applicability of SFASCDW are proved with experiments involving four datasets of various lengths in random locations using the three common attacks, namely insertion, reorder, and deletion. The SFASCDW was found to be effective and could be applicable in detecting any possible tampering.     

A robust zero-watermarking algorithm for copyright protection of text documents

The widespread use of Internet and other communication technologies has brought about ease in reproducing, disclosing and distributing digital content. In addition to getting the benefits of information exchange, the digital community is confronted with authentication, forgery and copyright protection issues. Text is the most frequently used medium travelling over the Internet, along with images, audio and video. Majority of the content of books, newspapers, web pages, advertisements, research papers, legal documents and many other documents is basically, plain text. Therefore, copyright protection of plain text is a most important issue. In this article, we propose a robust zero-watermarking algorithm based on prepositions and double letters for copyright protection of plain text. The embedding algorithm uses occurrences of prepositions and double letters in the text to generate a key based on watermark. The extraction algorithm extracts the watermark from the noisy text to identify the original owner. Experimental results illustrate the effectiveness of the proposed algorithm on text encountering combined insertion, deletion and re-ordering attacks, both in the dispersed and localized forms. The results are also compared to a recent work on text watermarking.     

Securing Arabic Contents Algorithm for Smart Detecting of Illegal Tampering Attacks

The most common digital media exchanged via the Internet is in text form. The Arabic language is considered one of the most sensitive languages of content modification due to the presence of diacritics that can cause a change in the meaning. In this paper, an intelligent scheme is proposed for improving the reliability and security of the text exchanged via the Internet. The core mechanism of the proposed scheme depends on integrating the hidden Markov model and zero text watermarking techniques. The watermark key will be generated by utilizing the extracted features of the text analysis process using the third order and word level of the Markov model. The Embedding and detection processes of the proposed scheme will be performed logically without the effect of the original text. The proposed scheme is implemented using PHP with VS code IDE. The simulation results, using varying sizes of standard datasets, show that the proposed scheme can obtain high reliability and provide better accuracy of the common illegal tampering attacks. Comparison results with other baseline techniques show the added value of the proposed scheme.     

Fragility and Robustness of Binary-Phase-Only-Filter-Based Fragile/Semifragile Digital Image Watermarking

In the fragile/semifragile digital image watermarking for image authentication, fragility or sensitivity of the embedded watermark to malicious attacks is an important problem. On the other hand, robustness to some incidental manipulations, such as JPEG compression, is required for the semifragile watermark. Recently, a binary-phase-only-fllter (BPOF)-based watermarking technique has been proposed for image authentication, where the authors embedded a watermark upon the BPOF of the Fourier spectrum of an image into the corresponding magnitude. Then, they performed image authentication by calculating the correlation between the extracted watermark and the phase information computed from the watermarked image. In this paper, we propose to use the identical ratio (IR) between the extracted watermark and the computed BPOF to detect watermark and measure the degree of authenticity. The IR is simpler, computationally efficient, and yields better watermark-detection performance when compared to the correlation-based calculation. In addition, it is found that the technique works better for fragile watermarking when compared to the semifragile watermarking. Furthermore, to accommodate semifragile watermarking, we propose to use the low-frequency ranges for watermark embedding and detection, which improves the required fragility and robustness. The performance of the improved algorithm is verified via experimental results.     

Optimal sub-band and strength selection for blind watermarking in wavelet domain

With increasing use of digital media, need for digital rights management has arisen. Watermarking is used to hide copyright protection information in the host medium. Hiding information to ensure digital right protection must ensure high imperceptibility and an acceptable level of robustness. In the watermark embedding, appropriate watermark strength and place selection in the host image is the most critical aspect of the whole process. Both watermark strength and place selection are considered as optimisation problems and are optimised using genetic algorithm (GA) and particle swarm optimisation (PSO). The watermark is embedded in the wavelet domain. With the proposed method optimal wavelet family, band, watermark strength and wavelet depth level are selected to ensure higher robustness and imperceptibility. The watermark is embedded in the selected bands of the wavelet packets. The band and wavelet depth is selected using GA and watermark strength is optimised using PSO method. The proposed method shows promising results against attacks on a variety of filters, i.e. low pass, high pass and median filters. Robustness results on JPEG compression and gaussian noise are also improved compared with the current approaches in practice.     

一种抗任意角度旋转的全息水印算法

目的针对目前数字水印在抗旋转攻击方面鲁棒性较差等问题,提出一种基于DWT变换和仿射变换的抗任意角度旋转的数字全息水印算法。方法首先对数字水印进行全息加密,保证水印的安全性;结合DWT变换,将水印信息嵌入载体图像;然后通过仿射变换实现图像的角度校正,进而实现抗任意角度旋转攻击及其他常见攻击。结果水印在受到各种攻击后,仍能被有效提取,尤其是抗任意角度旋转攻击,NC值均大于0.6。结论提出的算法对任意角度旋转攻击有较强的鲁棒性,可以有效地从含水印的图像中提取水印信息,保证了水印的安全性和有效性。     

面向便携式设备的数字水印检测方法

目的为了适应便携式数字水印检测时高抗打印拍照扫描及低算法复杂度的要求,提出一种基于ARM系统与基于离散小波变换和矩阵奇异值分解的数字水印算法相结合的便携式数字水印检测方法。方法在基于ARM便携式系统中,通过图像采集模块读取含水印图片信息,利用DWT-SVD数字水印算法进行水印检测,并在LCD上显示检测结果。结果基于ARM处理器的便携式设备,能够准确地检测出水印信息,提取水印NC值可达到0.7。结论该方法具有较好的抗打印拍照性能,且计算复杂度低,能够应用于携式数字水印检测设备。     

Robust image watermarking scheme against geometric attacks using a computer-generated hologram

Robustness against geometric attacks is one of the most important issues in digital watermarking. A novel geometric robust watermarking scheme that uses computer-generated holograms as the watermark is presented. To maintain imperceptibility and robustness, a quantization embedding algorithm is adopted to embed the mark hologram into the low-frequency subband of the wavelet-transformed host image. In the detection process, the geometric distorted watermarked images are recovered first by the proposed improved geometric correction method, which is based on the scale invariant feature transform, the invariant centroid, and the pulse coupled neural network. Then the mark holograms are extracted from the recovered images. In comparison with the traditional geometric estimation method, the suggested improved geometric correction method can estimate the geometric distortion parameters more accurately and needs less auxiliary information. Compared with other watermark schemes using digital holograms, the proposed method has the distinct advantage of robustness to geometric attacks. The experimental results demonstrate that the proposed method has good robustness to resist geometric attacks and common attacks including rotation, scaling, translation, image flipping, combined attacks, filtering, occlusion, cropping, and JPEG compression.     

A robust and secure watermarking scheme based on singular values replacement

Digital watermarking is an application associated with copyright protection. Any digital object can be used as a carrier to carry information. If the information is related to object then it is known as a watermark which can be visible or invisible. In the era of digital information, there are multiple danger zones like copyright and integrity violations, of digital object. In case of any dispute during rights violation, content creator can prove ownership by recovering the watermark. Two most important prerequisites for an efficient watermarking scheme are robustness and security. Watermark must be robust and recoverable even if a part of content is altered by one or more attacks like compression, filtering, geometric distortions, resizing, etc. In this work, we propose a blind watermarking scheme based on the discrete wavelet transform (DWT) and singular value decomposition (SVD). Singular values (SV??s) of high frequency (HH) band are used to optimize perceptual transparency and robustness constraints. Although most of the SVD-based schemes prove to be robust, little attention has been paid to their security aspect. Therefore, we introduce a signature-based authentication mechanism at the decoder to improve security. Resulting blind watermarking scheme is secure and robust.     

Digital watermarking based on fractal image coding

Abstract

With advances in computer network and multimedia technology, digital media are rapidly proliferating, and thus the issue of copyright protection for electronic publishing is receiving great attention. To achieve the goal of copyright protection, the digital watermarks are used to identify the owner of a certain image, so as to prevent illegal copying. Digital watermarking is the technique that embeds an invisible signal including owner identification and copy control information into multimedia data such as audio, video, and images. A new digital watermark approach based on fractal image coding is proposed in this paper. We present a way to use the fractal code as a means of embedding a watermark into image. The proposed approach has been shown to be resistant to general attacks, like StirMark. Moreover, someone who owns the decryption key can simply extract the digital watermark from the watermarked image without resorting to the original image.     

基于QR码的DWT-SVD数字水印算法

目的 结合奇异值和小波变换的优点, 针对彩色载体图像进行水印的嵌入和提取, 提高水印的鲁棒性和安全性。方法 根据基于DWT-SVD的数字水印算法, 对彩色载体图像进行RGB到Lab颜色空间的转换, 对L分量作二级离散小波变换, 选择低频子带并对其进行奇异值分解, 同时对原始QR码水印进行奇异值分解。最后根据人眼视觉系统 （HVS） 特性, 选择合适的嵌入强度因子嵌入水印。结果 文中算法对于高斯噪声、 椒盐噪声、 斑纹噪声和泊松噪声、 JPEG压缩、 小角度的旋转攻击、 缩放攻击以及对比度增强有一定的鲁棒性。结论 该算法能够抵抗常见的水印攻击, 满足数字防伪以及版权保护的需要。     

抗缩放攻击的高水印容量数字水印算法

目的 为了增加水印算法的可嵌入水印信息容量,解决抗高强度缩放攻击等问题,提出一种基于圆形角度模板的抗缩放攻击、高水印容量的数字水印算法。方法 首先将原始水印信息转换为QR码,根据QR码生成原理提取其数据编码,并进行分组,再将分组的编码转换为角度信息;随机生成具有方向性和周期性的基础圆形模板水印,根据角度信息对其进行旋转,生成待嵌入的圆形角度模板水印;通过修改图像的最小可察觉误差完成水印信息的嵌入;通过检测模板水印中的角度信息,提出水印信息。结果 实验结果表明,该算法不仅可有效抵抗高强度的缩放攻击,同时还可以抵抗色彩调整、旋转、压缩、噪声、滤波、模糊等攻击。此外,该算法可实现较高容量的水印信息嵌入和无损提取。结论 通过对水印信息预处理和圆形角度模板水印的应用,不仅使得该算法具备高水印容量,而且可有效抵抗高强度缩放攻击,在抵抗色彩调整、旋转等图像处理攻击方面同样具备较强的鲁棒性,能满足实际应用需求。     

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。     

支持隔行扫描的两步DCT域视频水印算法

提出了一种在隔行扫描MPEG-2视频流中嵌入DCT域水印的算法。该算法对MPEG-2中DCT变换按帧和按场进行的两种情况采用不同的扩频码进行嵌入和检测,使水印的检测基本不受DCT方式变化的影响,从而能够抵抗各种重编码攻击,同时也保持了良好的实时性。还采用了两步算法,即除水印数据外还同时嵌入了少量同步信息,这样既可定期更新用于水印数据的扩频码,从而提高算法的安全性与灵活性,同时在存在帧插入／删除等攻击时又不会因失去同步而导致检测失败。     

小波变换域互补鲁棒性视频多水印算法

数字水印是解决数字视频版权保护问题的一种有效技术手段.为了能同时抵抗几何攻击和时间域去同步攻击,本文提出了一种新的互补视频水印方案.根据视频序列的特点,沿时间轴嵌入第一个鲁棒水印,用以抵抗各种几何攻击;第二个鲁棒水印是借助静止图像水印技术在每一帧中嵌入,用以抵抗时间域去同步攻击.整个水印系统能互补地抵抗各种攻击形式,从而增强了算法的整体鲁棒性.水印的提取不需要原始视频信号.实验结果表明,该水印算法对帧丢失、帧插入等时间域去同步攻击以及几何攻击具有良好的鲁棒性.     

基于遗传算法的半脆弱水印方法研究

提出了一种基于遗传算法的自适应半脆弱图像水印方法,该方法要求水印对常见的操作具有鲁棒性,如JPEG压缩,而对其他的一些恶意操作具有脆弱性。根据图像局部区域的类型自适应地确定了水印的嵌入强度,用GA来优化了水印的嵌入位置。仿真结果表明,方法不会影响图像的主客观质量,而且可嵌入的水印信息量大。更为重要的是,方法可以准确确定恶意攻击的位置,显示了相比于其他方法的优越性。     

A Robust Image Watermarking Scheme Using Z-Transform,Discrete Wavelet Transform and Bidiagonal Singular Value Decomposition

Watermarking is a widely used solution to the problems of authentication and copyright protection of digital media especially for images, videos, and audio data. Chaos is one of the emerging techniques adopted in image watermarking schemes due to its intrinsic cryptographic properties. This paper proposes a new chaotic hybrid watermarking method combining Discrete Wavelet Transform (DWT), Z-transform (ZT) and Bidiagonal Singular Value Decomposition (BSVD). The original image is decomposed into 3-level DWT, and then, ZT is applied on the HH3 and HL3 sub-bands. The watermark image is encrypted using Arnold Cat Map. BSVD for the watermark and transformed original image were computed, and the watermark was embedded by modifying singular values of the host image with the singular values of the watermark image. Robustness of the proposed scheme was examined using standard test images and assessed against common signal processing and geometric attacks. Experiments indicated that the proposed method is transparent and highly robust.     

一种新的彩色图像变换域全息水印算法

提出了一种变换域中改善全息水印抗几何攻击和滤波攻击性能的彩色图像全息水印算法。 取彩色 RGB载体图像的蓝色通道,分块后做一级小波分解转换到变换域,取低频子带,然后进行奇异值分解嵌入数字全息水印。 实验结果表明:该算法水印隐蔽性好,重建的水印与原始水印相似度高;算法鲁棒性强,可以抵抗常见的各种攻击,尤其改善了全息水印的抗几何攻击和滤波攻击性能,满足了数字防伪、版权保护的需要。     

Design of a robust and secure digital signature scheme for image authentication over wireless channels

The introduction of 3G wireless communication systems, together with the invasive distribution of digital images and the growing concern on their originality triggers an emergent need of authenticating images received by unreliable channels, such as public Internet and wireless networks. To meet this need, a content-based image authentication scheme that is suitable for an insecure network and robust to transmission errors is proposed. The proposed scheme exploits the scalability of a structural digital signature in order to achieve a good trade off between security and image transfer for networked image applications. In this scheme, multi-scale features are used to make digital signatures robust to image degradations and keydependent parametric wavelet filters are employed to improve the security against forgery attacks. This scheme is also able to distinguish tampering areas in the attacked image. Experimental results show the robustness and validity of the proposed scheme.