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Embedding Color Watermarks in Color Images  [cached]
Tung-Lin Wu,Chun-Hsien Chou
EURASIP Journal on Advances in Signal Processing , 2003, DOI: 10.1155/s1687617203211227
Abstract: Robust watermarking with oblivious detection is essential to practical copyright protection of digital images. Effective exploitation of the characteristics of human visual perception to color stimuli helps to develop the watermarking scheme that fills the requirement. In this paper, an oblivious watermarking scheme that embeds color watermarks in color images is proposed. Through color gamut analysis and quantizer design, color watermarks are embedded by modifying quantization indices of color pixels without resulting in perceivable distortion. Only a small amount of information including the specification of color gamut, quantizer stepsize, and color tables is required to extract the watermark. Experimental results show that the proposed watermarking scheme is computationally simple and quite robust in face of various attacks such as cropping, low-pass filtering, white-noise addition, scaling, and JPEG compression with high compression ratios.
Graph Watermarks  [PDF]
Xiaohan Zhao,Qingyun Liu,Lin Zhou,Haitao Zheng,Ben Y. Zhao
Computer Science , 2015,
Abstract: From network topologies to online social networks, many of today's most sensitive datasets are captured in large graphs. A significant challenge facing owners of these datasets is how to share sensitive graphs with collaborators and authorized users, e.g. network topologies with network equipment vendors or Facebook's social graphs with academic collaborators. Current tools can provide limited node or edge privacy, but require modifications to the graph that significantly reduce its utility. In this work, we propose a new alternative in the form of graph watermarks. Graph watermarks are small graphs tailor-made for a given graph dataset, a secure graph key, and a secure user key. To share a sensitive graph G with a collaborator C, the owner generates a watermark graph W using G, the graph key, and C's key as input, and embeds W into G to form G'. If G' is leaked by C,its owner can reliably determine if the watermark W generated for C does in fact reside inside G', thereby proving C is responsible for the leak. Graph watermarks serve both as a deterrent against data leakage and a method of recourse after a leak. We provide robust schemes for creating, embedding and extracting watermarks, and use analysis and experiments on large, real graphs to show that they are unique and difficult to forge. We study the robustness of graph watermarks against both single and powerful colluding attacker models, then propose and empirically evaluate mechanisms to dramatically improve resilience.
Computational Tools and Algorithms for Designing Customized Synthetic Genes  [PDF]
Nathan Gould,Oliver Hendy,Dimitris Papamichail
Frontiers in Bioengineering and Biotechnology , 2014, DOI: 10.3389/fbioe.2014.00041
Abstract: Advances in DNA synthesis have enabled the construction of artificial genes, gene circuits, and genomes of bacterial scale. Freedom in de novo design of synthetic constructs provides significant power in studying the impact of mutations in sequence features, and verifying hypotheses on the functional information that is encoded in nucleic and amino acids. To aid this goal, a large number of software tools of variable sophistication have been implemented, enabling the design of synthetic genes for sequence optimization based on rationally defined properties. The first generation of tools dealt predominantly with singular objectives such as codon usage optimization and unique restriction site incorporation. Recent years have seen the emergence of sequence design tools that aim to evolve sequences toward combinations of objectives. The design of optimal protein-coding sequences adhering to multiple objectives is computationally hard, and most tools rely on heuristics to sample the vast sequence design space. In this review, we study some of the algorithmic issues behind gene optimization and the approaches that different tools have adopted to redesign genes and optimize desired coding features. We utilize test cases to demonstrate the efficiency of each approach, as well as identify their strengths and limitations.
Survey on Digital Video Watermarking Techniques and Attacks on Watermarks
International Journal of Engineering Science and Technology , 2010,
Abstract: Digital video watermarking is a technique for embedding additional data along with video signal. Embedded data is used for copyright owner identification. A number of video watermarking techniques are proposed.These techniques exploit different ways in order to embed a robust watermark and to maintain the original video signal fidelity. In this paper, Digital video watermarking techniques and attacks on watermarks are presented.
DNA watermarks in non-coding regulatory sequences
Dominik Heider, Martin Pyka, Angelika Barnekow
BMC Research Notes , 2009, DOI: 10.1186/1756-0500-2-125
Abstract: The lac promoter was deactivated by the integrated watermark. In addition, the RNA molecules displayed altered configurations after introducing a watermark, but surprisingly were functionally intact, which has been verified by analyzing the growth characteristics of both wild type and watermarked scR1 transformed yeast cells. In a third approach we introduced a second overlapping watermark into the lac promoter, which did not affect the promoter activity.Even though the watermarked RNA and one of the watermarked promoters did not show any significant differences compared to the wild type RNA and wild type promoter region, respectively, it cannot be generalized that other RNA molecules or regulatory sequences behave accordingly. Therefore, we do not recommend integrating watermark sequences into regulatory regions.DNA watermarks can be used for authenticating genetically modified organisms or in future for labeling animals in breeding [1,2]. It has already been shown in silico and in vivo that these watermarks do not affect the translation of proteins [1-4]. These assumptions only apply to coding regions, thus the insertion of watermarks into regulatory sequences like promoter regions or regulatory RNA molecules, had to be examined. In our studies we integrated watermark sequences into a widely known promoter region of bacteria. Watermarks integrated into regulatory regions like promoter or enhancer sequences can affect their functionality. We integrated watermark sequences into the lac promoter of Escherichia coli to examine, whether the watermarks affect the promoter activity. The lac operon of Escherichia coli consists of a promoter, three operators and three genes (lacY, lacZ and lacA), coding for the β-galactoside permease, β-galactosidase and β-galactoside transacetylase, which are required for the lactose metabolism in Escherichia coli [5]. The β-galactosidase cleaves the lactose into glucose and galactose [5]. The promoter sequence of the lac operon consists
Annotating novel genes by integrating synthetic lethals and genomic information
Daniel Sch?ner, Markus Kalisch, Christian Leisner, Lukas Meier, Marc Sohrmann, Mahamadou Faty, Yves Barral, Matthias Peter, Wilhelm Gruissem, Peter Bühlmann
BMC Systems Biology , 2008, DOI: 10.1186/1752-0509-2-3
Abstract: We analyze synthetic lethality data for arp1 and jnm1, two spindle migration genes, in order to identify novel members in this process. To this end, we use an unsupervised statistical method that integrates additional information from biological data sources, such as gene expression, phenotypic profiling, RNA degradation and sequence similarity. Different from existing methods that require large amounts of synthetic lethal data, our method merely relies on synthetic lethality information from two single screens. Using a Multivariate Gaussian Mixture Model, we determine the best subset of features that assign the target genes to two groups. The approach identifies a small group of genes as candidates involved in spindle migration. Experimental testing confirms the majority of our candidates and we present she1 (YBL031W) as a novel gene involved in spindle migration. We applied the statistical methodology also to TOR2 signaling as another example.We demonstrate the general use of Multivariate Gaussian Mixture Modeling for selecting candidate genes for experimental characterization from synthetic lethality data sets. For the given example, integration of different data sources contributes to the identification of genetic interaction partners of arp1 and jnm1 that play a role in the same biological process.One of the major challenges in computational biology is the extraction of relevant information from the increasing amounts of data resulting from large scale experimentation. While the reliability of the results of single high-throughput assays has often been challenged, there is great promise that the confidence and precision of the outcomes can be increased through integration and combination of multiple data sources. We applied statistical modeling, based on data integration, for finding yeast genes involved in spindle migration from two synthetic lethality screens performed with arp1 and jnm1.Synthetic lethality describes the phenomenon of observing a lethal pheno
Kazuo Ohzeki,,Yuki Seo,,Engyoku Gi
International Journal of Computer Science & Applications , 2010,
The History of Some Watermarks in Manuscripts of the 19 th Century
Azza Mahmoud Aly
Cybrarians Journal , 2005,
Abstract: A Research about the watermarks in Manuscripts of the 19 th Century, it show every watermark and gives its history and description and position.
Invisible Flow Watermarks for Channels with Dependent Substitution, Deletion, and Bursty Insertion Errors  [PDF]
Xun Gong,Mavis Rodrigues,Negar Kiyavash
Computer Science , 2013,
Abstract: Flow watermarks efficiently link packet flows in a network in order to thwart various attacks such as stepping stones. We study the problem of designing good flow watermarks. Earlier flow watermarking schemes mostly considered substitution errors, neglecting the effects of packet insertions and deletions that commonly happen within a network. More recent schemes consider packet deletions but often at the expense of the watermark visibility. We present an invisible flow watermarking scheme capable of enduring a large number of packet losses and insertions. To maintain invisibility, our scheme uses quantization index modulation (QIM) to embed the watermark into inter-packet delays, as opposed to time intervals including many packets. As the watermark is injected within individual packets, packet losses and insertions may lead to watermark desynchronization and substitution errors. To address this issue, we add a layer of error-correction coding to our scheme. Experimental results on both synthetic and real network traces demonstrate that our scheme is robust to network jitter, packet drops and splits, while remaining invisible to an attacker.
Fractal Image Coding with Digital Watermarks
M. Candik,D. Levicky,Z. Klenovicova
Radioengineering , 2000,
Abstract: In this paper are presented some results of implementation of digitalwatermarking methods into image coding based on fractal principles. Thepaper focuses on two possible approaches of embedding digitalwatermarks into fractal code of images - embedding digital watermarksinto parameters for position of similar blocks and coefficients ofblock similarity. Both algorithms were analyzed and verified on grayscale static images.
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