291,167 research outputs found

    Capacity of DNA Data Embedding Under Substitution Mutations

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    A number of methods have been proposed over the last decade for encoding information using deoxyribonucleic acid (DNA), giving rise to the emerging area of DNA data embedding. Since a DNA sequence is conceptually equivalent to a sequence of quaternary symbols (bases), DNA data embedding (diversely called DNA watermarking or DNA steganography) can be seen as a digital communications problem where channel errors are tantamount to mutations of DNA bases. Depending on the use of coding or noncoding DNA hosts, which, respectively, denote DNA segments that can or cannot be translated into proteins, DNA data embedding is essentially a problem of communications with or without side information at the encoder. In this paper the Shannon capacity of DNA data embedding is obtained for the case in which DNA sequences are subject to substitution mutations modelled using the Kimura model from molecular evolution studies. Inferences are also drawn with respect to the biological implications of some of the results presented.Comment: 22 pages, 13 figures; preliminary versions of this work were presented at the SPIE Media Forensics and Security XII conference (January 2010) and at the IEEE ICASSP conference (March 2010

    A generalization of the integer linear infeasibility problem

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    Does a given system of linear equations with nonnegative constraints have an integer solution? This is a fundamental question in many areas. In statistics this problem arises in data security problems for contingency table data and also is closely related to non-squarefree elements of Markov bases for sampling contingency tables with given marginals. To study a family of systems with no integer solution, we focus on a commutative semigroup generated by a finite subset of Zd\Z^d and its saturation. An element in the difference of the semigroup and its saturation is called a ``hole''. We show the necessary and sufficient conditions for the finiteness of the set of holes. Also we define fundamental holes and saturation points of a commutative semigroup. Then, we show the simultaneous finiteness of the set of holes, the set of non-saturation points, and the set of generators for saturation points. We apply our results to some three- and four-way contingency tables. Then we will discuss the time complexities of our algorithms.Comment: This paper has been published in Discrete Optimization, Volume 5, Issue 1 (2008) p36-5

    Environmental Security Factors and Sustainable Natural Resource Management: The Case of Choke Mountain Watersheds, East Gojjam, Ethiopia

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    Through sound governance, accountable management and sustainable utilization of natural resource and environment takes effective steps towards promoting or creating social, economic, and political stability and insuring the common welfare of the country. This paper assesses the existing environmental security and identified critical environmental concerns or issues on bases of natural resource utilization, management and governance. A cross-sectional survey design was employed in this study. Questionnaire survey, key informant interview, focus group discussion, field observation and secondary data sources, were utilized to generate the data required for the analysis. Both qualitative and quantitative analysis approach, descriptive analysis and analytical technique like chi-square tests were employed to analyze the data.Finding of the study revealed that an environmental insecurity (scarcity of natural resource, conflict on natural resource utilization, migration and unemployment) were occurred in the study area. This insecurity happened mainly because of natural resource utilization problem by the community, natural resource management and governance problem by the government are considered as a secondary and third factors respectively.The common critical environmental concern that threats the sustainability of land and forest resources in the study area, (Choke Mountain) in general includes: Scarcity of agricultural land, soil erosion, deforestation, exact district and kebele demarcation problem and poor land use practices.VSTM analysis model has been employed so as to identify major environmental security factors of each critical environmental concerns or issues. These are: for scarcity of cultivation land the major environmental security factor is population pressure, for soil erosion deforestation and slope of the land, for deforestation free grazing scarcity of cultivation land and high demand of fuel wood, for exact district and kebele demarcation problem population expansion to choke mountain and for poor land use practices absence of reaching land use planning implementation document from regional rural land administration office are the main and important security factors for the occurrence of those listed above critical environmental concerns or issues. Keywords: Critical Environmental Concern, VSTM analysis, Environmental Insecurit

    Examining the Effects of Cultural Dimensions on Deviant IS Use Behaviour in a Developing Economy Context

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    Information System (IS) tools and applications create opportunities for a positive digital change to all individuals and organizations in the global workplace to improve competitiveness and quality of work life. Recent studies have shown that the most problematic areas in IS security incidences are people-related factors. In this regard, employees are causing IS security risks and vulnerabilities as they use those resources, especially by exercising their legitimate and lawful rights, mainly because people are the weakest link on IS security matters. On the one hand, the effects of organizational sanctions are not always effective due to socio-cultural variabilities, and so far they have not been able to fully defend employee related IS misuse or misconduct. On the other hand, the use of neutralization techniques supports individuals to justify their deviant actions, but differently to people in different socio-cultural bases. To examine such a problem, therefore, culture as a moderator, criminological constructs and level of employees’ awareness to IS security as independent variables are employed to explain IS misuse intention in unison are proposed through a comprehensive conceptual research model. A positivist research paradigm using a cross-sectional quantitative survey data collection approach will be adapted to help empirically test the model. To validate the model and its constructs, the study will apply SEM-PLS data analysis techniques using Smart-PLS and SPSS with Amos. Finally, this study in progress discusses the potential practical and theoretical contributions and plans to provide scientific evidence based on its findings

    Security and Data Analysis : Three Case Studies

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    In recent years, techniques to automatically analyze lots of data have advanced significantly. The possibility to gather and analyze large amounts of data has challenged security research in two unique ways. First, the analysis of Big Data can threaten users’ privacy by merging and connecting data from different sources. Chapter 2 studies how patients’ medical data can be protected in a world where Big Data techniques can be used to easily analyze large amounts of DNA data. Second, Big Data techniques can be used to improve the security of software systems. In Chapter 4 I analyzed data gathered from internet-wide certificate scans to make recommendations on which certificate authorities can be removed from trust stores. In Chapter 5 I analyzed open source repositories to make predicitions of which commits introduced security-critical bugs. In total, I present three case studies that explore the application of data analysis – “Big Data” – to system security. By considering not just isolated examples but whole ecosystems, the insights become much more solid, and the results and recommendations become much stronger. Instead of manually analyzing a couple of mobile apps, we have the ability to consider a security-critical mistake in all applications of a given platform. We can identify systemic errors all developers of a given platform, a given programming language or a given security paradigm make – and fix it with the certainty that we truly found the core of the problem. Instead of manually analyzing the SSL installation of a couple of websites, we can consider all certificates – in times of Certificate Transparency even with historical data of issued certificates – and make conclusions based on the whole ecosystem. We can identify rogue certificate authorities as well as monitor the deployment of new TLS versions and features and make recommendations based on those. And instead of manually analyzing open source code bases for vulnerabilities, we can apply the same techniques and again consider all projects on e.g. GitHub. Then, instead of just fixing one vulnerability after the other, we can use these insights to develop better tooling, easier-to-use security APIs and safer programming languages

    Understanding and protecting closed-source systems through dynamic analysis

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    In this dissertation, we focus on dynamic analyses that examine the data handled by programs and operating systems in order to divine the undocumented constraints and implementation details that determine their behavior in the field. First, we introduce a novel technique for uncovering the constraints actually used in OS kernels to decide whether a given instance of a kernel data structure is valid. Next, we tackle the semantic gap problem in virtual machine security: we present a pair of systems that allow, on the one hand, automatic extraction of whole-system algorithms for collecting information about a running system, and, on the other, the rapid identification of “hook points” within a system or program where security tools can interpose to be notified of security-relevant events. Finally, we present and evaluate a new dynamic measure of code similarity that examines the content of the data handled by the code, rather than the syntactic structure of the code itself. This problem has implications both for understanding the capabilities of novel malware as well as understanding large binary code bases such as operating system kernels.Ph.D

    Mobile Deployable Bases and Ports: A Study for Interim Requirements

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    Logistics is an age old problem that has been the key to the greatest victories and defeats in history. Maritime support of wartime land campaigns as well as conflicts at sea, has been the answer to that problem even as far back in history as the ancient Greek Empire. Throughout the ages however the lesson that seems to be learned and relearned, the hard way, is that of logistic support. Today the United States is faced with what, to some seems to be an overwhelming problem in logistic support overseas, particularly in the maritime transportation and support arena. The U.S. flag merchant fleet is in no position to support even a medium sized conflict overseas. At the same tie, our peacetime logistic security is continually threatened by the ebb and flow of other friendly nations\u27 political attitudes. One option is the development of deployable mobile base and port structures. In many ways less expensive than permanent oversea basing facilities, mobile bases/ports could be a solution to some of the current maritime logistics woes of the U.S. By providing an alternative to fixed sea/air bases, the above two problems could be diminished. In addition, mobile overseas base facilities could provide military commanders with new strategic and tactical options during a crisis or conflict. They could give new meaning to the term disaster relief or even one day provide new economic options for entire nations. The technology for giant mobile ocean bases exists, but the capability to efficiently produce and use such facilities are still fifteen to twenty years away. In the interim, there is still a need for a mobile base capability. Use of existing offshore construction and mining operations equipment such as various drilling platform designs, giant support barges and floating port construction methods can fill the gap. There is historic and up to date data on the use of such designs for a multitude of purposes, including those stated above. An analysis of currently available equipment and capabilities can aid in making a choice, but as always cost effectiveness is a major factor in the decision. In this case however, there are high stakes in political costs as well as capital costs
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