272 resultados para P2P piracy
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Treatise in which Daniel Defoe sets out his arguments concerning the importance of maintaining a free press, as well as the need to provide for a statutory protection to prevent the ‘press-piracy' of published books.
Defoe sets out various public interest arguments concerning the encouragement of learning, industry and the arts, in support of his case for the introduction of copyright legislation. The commentary describes part of the background to the passing of the Statute of Anne 1710 (uk_1710), in particular: the various unsuccessful attempts to reintroduce an alternative to the Licensing Act 1662 (uk_1662); Defoe's public writing on the need for, and social value of, copyright protection; and the influence of his writings in providing the Company of Stationers with a new rhetorical strategy with which to lobby parliament and secure the passing of the Statute of Anne.
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We consider the problem of resource selection in clustered Peer-to-Peer Information Retrieval (P2P IR) networks with cooperative peers. The clustered P2P IR framework presents a significant departure from general P2P IR architectures by employing clustering to ensure content coherence between resources at the resource selection layer, without disturbing document allocation. We propose that such a property could be leveraged in resource selection by adapting well-studied and popular inverted lists for centralized document retrieval. Accordingly, we propose the Inverted PeerCluster Index (IPI), an approach that adapts the inverted lists, in a straightforward manner, for resource selection in clustered P2P IR. IPI also encompasses a strikingly simple peer-specific scoring mechanism that exploits the said index for resource selection. Through an extensive empirical analysis on P2P IR testbeds, we establish that IPI competes well with the sophisticated state-of-the-art methods in virtually every parameter of interest for the resource selection task, in the context of clustered P2P IR.
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info:eu-repo/semantics/published
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Contemporary integrated circuits are designed and manufactured in a globalized environment leading to concerns of piracy, overproduction and counterfeiting. One class of techniques to combat these threats is circuit obfuscation which seeks to modify the gate-level (or structural) description of a circuit without affecting its functionality in order to increase the complexity and cost of reverse engineering. Most of the existing circuit obfuscation methods are based on the insertion of additional logic (called “key gates”) or camouflaging existing gates in order to make it difficult for a malicious user to get the complete layout information without extensive computations to determine key-gate values. However, when the netlist or the circuit layout, although camouflaged, is available to the attacker, he/she can use advanced logic analysis and circuit simulation tools and Boolean SAT solvers to reveal the unknown gate-level information without exhaustively trying all the input vectors, thus bringing down the complexity of reverse engineering. To counter this problem, some ‘provably secure’ logic encryption algorithms that emphasize methodical selection of camouflaged gates have been proposed previously in literature [1,2,3]. The contribution of this paper is the creation and simulation of a new layout obfuscation method that uses don't care conditions. We also present proof-of-concept of a new functional or logic obfuscation technique that not only conceals, but modifies the circuit functionality in addition to the gate-level description, and can be implemented automatically during the design process. Our layout obfuscation technique utilizes don’t care conditions (namely, Observability and Satisfiability Don’t Cares) inherent in the circuit to camouflage selected gates and modify sub-circuit functionality while meeting the overall circuit specification. Here, camouflaging or obfuscating a gate means replacing the candidate gate by a 4X1 Multiplexer which can be configured to perform all possible 2-input/ 1-output functions as proposed by Bao et al. [4]. It is important to emphasize that our approach not only obfuscates but alters sub-circuit level functionality in an attempt to make IP piracy difficult. The choice of gates to obfuscate determines the effort required to reverse engineer or brute force the design. As such, we propose a method of camouflaged gate selection based on the intersection of output logic cones. By choosing these candidate gates methodically, the complexity of reverse engineering can be made exponential, thus making it computationally very expensive to determine the true circuit functionality. We propose several heuristic algorithms to maximize the RE complexity based on don’t care based obfuscation and methodical gate selection. Thus, the goal of protecting the design IP from malicious end-users is achieved. It also makes it significantly harder for rogue elements in the supply chain to use, copy or replicate the same design with a different logic. We analyze the reverse engineering complexity by applying our obfuscation algorithm on ISCAS-85 benchmarks. Our experimental results indicate that significant reverse engineering complexity can be achieved at minimal design overhead (average area overhead for the proposed layout obfuscation methods is 5.51% and average delay overhead is about 7.732%). We discuss the strengths and limitations of our approach and suggest directions that may lead to improved logic encryption algorithms in the future. References: [1] R. Chakraborty and S. Bhunia, “HARPOON: An Obfuscation-Based SoC Design Methodology for Hardware Protection,” IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, vol. 28, no. 10, pp. 1493–1502, 2009. [2] J. A. Roy, F. Koushanfar, and I. L. Markov, “EPIC: Ending Piracy of Integrated Circuits,” in 2008 Design, Automation and Test in Europe, 2008, pp. 1069–1074. [3] J. Rajendran, M. Sam, O. Sinanoglu, and R. Karri, “Security Analysis of Integrated Circuit Camouflaging,” ACM Conference on Computer Communications and Security, 2013. [4] Bao Liu, Wang, B., "Embedded reconfigurable logic for ASIC design obfuscation against supply chain attacks,"Design, Automation and Test in Europe Conference and Exhibition (DATE), 2014 , vol., no., pp.1,6, 24-28 March 2014.
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Tese (doutorado)—Universidade de Brasília, Instituto de Artes, Departamento de Artes Visuais, Programa de Pós-Graduação em Arte, 2015.
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Doutoramento em Estudos de Desenvolvimento
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Mestrado em Marketing
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En este trabajo se presenta la investigación realizada con el objeto de determinar la factibilidad tecnológica para el registro de los hologramas de matriz de punto utilizados ampliamente en la industria de las artes gráficas como elementos de seguridad en la lucha contra la piratería y la falsificación de productos -- Para ello se estudian y presentan los fundamentos ópticos de las rejillas de difracción que los conforman, derivando los métodos que permiten el cálculo a partir de condiciones establecidas de iluminación y reconstrucción -- A partir de dichos métodos se desarrollan y se ponen en funcionamiento sistemas y arreglos experimentales completos, que involucran el software para el control de los dispositivos mecánicos, para el manejo y diseño de las imágenes, y adicionalmente la óptica propiamente dicha -- Los sistemas de esta forma implementados, que permiten la generación y registro de las rejillas, son puestos a prueba y se presentan los resultados tomando como parámetro la medición de los espectros generados por difracción -- Finalmente se presentan y evalúan varios ejemplos típicos de la aplicación de los hologramas de seguridad generados en el sistema desarrollado
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41 p.
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A life of piracy offered marginal men a profession with a degree of autonomy, despite the brand of “outlaw” and the fear of prosecution. At various times throughout history, governments and crowned heads suspended much of their piracy prosecution, licensing men to work as “privateers” for the state, supplementing naval forces. This practice has a long history, but in sixteenth-century England, Elizabeth I (1558-1603) significantly altered this tradition. Recognizing her own weakness in effectively prosecuting these men and the profit they could contribute to the government, Elizabeth began incorporating pirates into the English naval corps in peacetime—not just in war. This practice increased English naval resources, income, and presence in the emerging Atlantic World, but also increased conflict with the powerful Spanish empire. By 1605, making peace with Spain, James VI/I (1603-1625) retracted Elizabeth’s privateering promotion, prompting an emigration of English seamen to the American outposts they had developed in the previous century. Now exiles, no longer beholden to the Crown, seamen reverted back to piracy. The Carolinas and Jamaica served as bases for these rover communities. In 1650, the revolutionary leader Oliver Cromwell (1649-1658) once again recognized the merits of such policies. Determined to demonstrate his authority and solidify his rule, Cromwell offered citizenship and state support to Caribbean exiles in exchange for their aiding of his navy in the taking of Spanish Jamaica. Official chartering of Port Royal, Jamaica served as reward for these men’s efforts and as the culmination of a century-long cycle of piracy legislation, creating one of England’s most lucrative colonies in the middle of a traditionally Spanish Caribbean empire. Through legal and diplomatic records, correspondence, and naval and demographic records from England and Spain, this dissertation explores early modern piracy/privateering policy and its impact on the development of the Atlantic World. European disputes and imperial competition converged in these piracy debates with significant consequences for the definitions of criminality and citizenship and for the development of Atlantic empire.
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Polylysogeny is frequently considered to be the result of an adaptive evolutionary process in which prophages confer fitness and/or virulence factors, thus making them important for evolution of both bacterial populations and infectious diseases. The Enterococcus faecalis V583 isolate belongs to the high-risk clonal complex 2 that is particularly well adapted to the hospital environment. Its genome carries 7 prophage-like elements (V583-pp1 to -pp7), one of which is ubiquitous in the species. In this study, we investigated the activity of the V583 prophages and their contribution to E. faecalis biological traits. We systematically analyzed the ability of each prophage to excise from the bacterial chromosome, to replicate and to package its DNA. We also created a set of E. faecalis isogenic strains that lack from one to all six non-ubiquitous prophages by mimicking natural excision. Our work reveals that prophages of E. faecalis V583 excise from the bacterial chromosome in the presence of a fluoroquinolone, and are able to produce active phage progeny. Intricate interactions between V583 prophages were also unveiled: i) pp7, coined EfCIV583 for E. faecalis chromosomal island of V583, hijacks capsids from helper phage 1, leading to the formation of distinct virions, and ii) pp1, pp3 and pp5 inhibit excision of pp4 and pp6. The hijacking exerted by EfCIV583 on helper phage 1 capsids is the first example of molecular piracy in Gram positive bacteria other than staphylococci. Furthermore, prophages encoding platelet-binding-like proteins were found to be involved in adhesion to human platelets, considered as a first step towards the development of infective endocarditis. Our findings reveal not only a role of E. faecalis V583 prophages in pathogenicity, but also provide an explanation for the correlation between antibiotic usage and E. faecalis success as a nosocomial pathogen, as fluoriquinolone may provoke release of prophages and promote gene dissemination among isolates.
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Chaque année, le piratage mondial de la musique coûte plusieurs milliards de dollars en pertes économiques, pertes d’emplois et pertes de gains des travailleurs ainsi que la perte de millions de dollars en recettes fiscales. La plupart du piratage de la musique est dû à la croissance rapide et à la facilité des technologies actuelles pour la copie, le partage, la manipulation et la distribution de données musicales [Domingo, 2015], [Siwek, 2007]. Le tatouage des signaux sonores a été proposé pour protéger les droit des auteurs et pour permettre la localisation des instants où le signal sonore a été falsifié. Dans cette thèse, nous proposons d’utiliser la représentation parcimonieuse bio-inspirée par graphe de décharges (spikegramme), pour concevoir une nouvelle méthode permettant la localisation de la falsification dans les signaux sonores. Aussi, une nouvelle méthode de protection du droit d’auteur. Finalement, une nouvelle attaque perceptuelle, en utilisant le spikegramme, pour attaquer des systèmes de tatouage sonore. Nous proposons tout d’abord une technique de localisation des falsifications (‘tampering’) des signaux sonores. Pour cela nous combinons une méthode à spectre étendu modifié (‘modified spread spectrum’, MSS) avec une représentation parcimonieuse. Nous utilisons une technique de poursuite perceptive adaptée (perceptual marching pursuit, PMP [Hossein Najaf-Zadeh, 2008]) pour générer une représentation parcimonieuse (spikegramme) du signal sonore d’entrée qui est invariante au décalage temporel [E. C. Smith, 2006] et qui prend en compte les phénomènes de masquage tels qu’ils sont observés en audition. Un code d’authentification est inséré à l’intérieur des coefficients de la représentation en spikegramme. Puis ceux-ci sont combinés aux seuils de masquage. Le signal tatoué est resynthétisé à partir des coefficients modifiés, et le signal ainsi obtenu est transmis au décodeur. Au décodeur, pour identifier un segment falsifié du signal sonore, les codes d’authentification de tous les segments intacts sont analysés. Si les codes ne peuvent être détectés correctement, on sait qu’alors le segment aura été falsifié. Nous proposons de tatouer selon le principe à spectre étendu (appelé MSS) afin d’obtenir une grande capacité en nombre de bits de tatouage introduits. Dans les situations où il y a désynchronisation entre le codeur et le décodeur, notre méthode permet quand même de détecter des pièces falsifiées. Par rapport à l’état de l’art, notre approche a le taux d’erreur le plus bas pour ce qui est de détecter les pièces falsifiées. Nous avons utilisé le test de l’opinion moyenne (‘MOS’) pour mesurer la qualité des systèmes tatoués. Nous évaluons la méthode de tatouage semi-fragile par le taux d’erreur (nombre de bits erronés divisé par tous les bits soumis) suite à plusieurs attaques. Les résultats confirment la supériorité de notre approche pour la localisation des pièces falsifiées dans les signaux sonores tout en préservant la qualité des signaux. Ensuite nous proposons une nouvelle technique pour la protection des signaux sonores. Cette technique est basée sur la représentation par spikegrammes des signaux sonores et utilise deux dictionnaires (TDA pour Two-Dictionary Approach). Le spikegramme est utilisé pour coder le signal hôte en utilisant un dictionnaire de filtres gammatones. Pour le tatouage, nous utilisons deux dictionnaires différents qui sont sélectionnés en fonction du bit d’entrée à tatouer et du contenu du signal. Notre approche trouve les gammatones appropriés (appelés noyaux de tatouage) sur la base de la valeur du bit à tatouer, et incorpore les bits de tatouage dans la phase des gammatones du tatouage. De plus, il est montré que la TDA est libre d’erreur dans le cas d’aucune situation d’attaque. Il est démontré que la décorrélation des noyaux de tatouage permet la conception d’une méthode de tatouage sonore très robuste. Les expériences ont montré la meilleure robustesse pour la méthode proposée lorsque le signal tatoué est corrompu par une compression MP3 à 32 kbits par seconde avec une charge utile de 56.5 bps par rapport à plusieurs techniques récentes. De plus nous avons étudié la robustesse du tatouage lorsque les nouveaux codec USAC (Unified Audion and Speech Coding) à 24kbps sont utilisés. La charge utile est alors comprise entre 5 et 15 bps. Finalement, nous utilisons les spikegrammes pour proposer trois nouvelles méthodes d’attaques. Nous les comparons aux méthodes récentes d’attaques telles que 32 kbps MP3 et 24 kbps USAC. Ces attaques comprennent l’attaque par PMP, l’attaque par bruit inaudible et l’attaque de remplacement parcimonieuse. Dans le cas de l’attaque par PMP, le signal de tatouage est représenté et resynthétisé avec un spikegramme. Dans le cas de l’attaque par bruit inaudible, celui-ci est généré et ajouté aux coefficients du spikegramme. Dans le cas de l’attaque de remplacement parcimonieuse, dans chaque segment du signal, les caractéristiques spectro-temporelles du signal (les décharges temporelles ;‘time spikes’) se trouvent en utilisant le spikegramme et les spikes temporelles et similaires sont remplacés par une autre. Pour comparer l’efficacité des attaques proposées, nous les comparons au décodeur du tatouage à spectre étendu. Il est démontré que l’attaque par remplacement parcimonieux réduit la corrélation normalisée du décodeur de spectre étendu avec un plus grand facteur par rapport à la situation où le décodeur de spectre étendu est attaqué par la transformation MP3 (32 kbps) et 24 kbps USAC.
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Staphylococcal pathogenicity islands (SaPIs), the prototype members of the family of phage inducible chromosomal islands (PICIs), are extremely mobile phage satellites, which are transferred between bacterial hosts after their induction by a helper phage. The intimate relationship between SaPIs and their helper phages is one of the most studied examples of virus satellite interactions in prokaryotic cells. SaPIs encode and disseminate virulence and fitness factors, representing a driving force for bacterial adaptation and pathogenesis. Many SaPIs encode a conserved morphogenetic operon, including a core set of genes whose function allows them to parasitize and exploit the phage life cycle. One of the central mechanisms of this molecular piracy is the specific packaging of the SaPI genomes into reduced sized capsid structures derived from phage proteins. Pac phages were classically thought to be the only phages involved in the mobilisation of phage-mediated virulence genes, including the transfer of SaPIs within related and non-related bacteria. This study presents the involvement of S. aureus cos phages in the intra- and intergeneric transfer of cos SaPIs for the first time. A novel example of molecular parasitism is shown, by which this newly characterised group of cos SaPIs uses two distinct and complementary mechanisms to take over the helper phage packaging machinery for their own reproduction. SaPIbov5, the prototype of the cos SaPIs, does not encode the characteristic morphogenetic operon found in pac SaPIs. However, cos SaPIs features both pac and cos phage cleavage sequences in their genome, ensuring SaPI packaging in small- and full-sized phage particles, depending on the helper phage. Moreover, cos-site packaging in S. aureus was shown to require the activity of a phage HNH nuclease. The HNH protein functions together with the large terminase subunit, triggering cleavage and melting of the cos-site sequence. In addition, a novel piracy strategy, severely interfering with the helper phage reproduction, was identified in cos SaPIs and characterised. This mechanism of piracy depends on the cos SaPI-encoded ccm gene, which encodes a capsid protein involved in the formation of small phage particles, modifying the assembling process via a scaffolding mechanism. This strategy resembles the ones described for pac SaPIs and represents a remarkable example of convergent evolution. A further convergent mechanism of capsid size-reduction was identified and characterised for the Enterococcus faecalis EfCIV583 pathogenicity island, another member of the PICI family. In this case, the self-encoded CpmE conducts this molecular piracy through a putative scaffolding function. Similar to cos SaPIs, EfCIV583 carries the helper phage cleavage sequence in its genome enabling its mobilisation by the phage terminase complex. The results presented in this thesis show how two examples of non-related members of the PICI family follow the same evolutionary convergent strategy to interfere with their helper phage. These findings could indicate that the described strategies might be widespread among PICIs and implicate a significant impact of PICIs mediated-virulence gene transfer in bacterial evolution and the emergence of pathogenic bacteria.
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Conventional web search engines are centralised in that a single entity crawls and indexes the documents selected for future retrieval, and the relevance models used to determine which documents are relevant to a given user query. As a result, these search engines suffer from several technical drawbacks such as handling scale, timeliness and reliability, in addition to ethical concerns such as commercial manipulation and information censorship. Alleviating the need to rely entirely on a single entity, Peer-to-Peer (P2P) Information Retrieval (IR) has been proposed as a solution, as it distributes the functional components of a web search engine – from crawling and indexing documents, to query processing – across the network of users (or, peers) who use the search engine. This strategy for constructing an IR system poses several efficiency and effectiveness challenges which have been identified in past work. Accordingly, this thesis makes several contributions towards advancing the state of the art in P2P-IR effectiveness by improving the query processing and relevance scoring aspects of a P2P web search. Federated search systems are a form of distributed information retrieval model that route the user’s information need, formulated as a query, to distributed resources and merge the retrieved result lists into a final list. P2P-IR networks are one form of federated search in routing queries and merging result among participating peers. The query is propagated through disseminated nodes to hit the peers that are most likely to contain relevant documents, then the retrieved result lists are merged at different points along the path from the relevant peers to the query initializer (or namely, customer). However, query routing in P2P-IR networks is considered as one of the major challenges and critical part in P2P-IR networks; as the relevant peers might be lost in low-quality peer selection while executing the query routing, and inevitably lead to less effective retrieval results. This motivates this thesis to study and propose query routing techniques to improve retrieval quality in such networks. Cluster-based semi-structured P2P-IR networks exploit the cluster hypothesis to organise the peers into similar semantic clusters where each such semantic cluster is managed by super-peers. In this thesis, I construct three semi-structured P2P-IR models and examine their retrieval effectiveness. I also leverage the cluster centroids at the super-peer level as content representations gathered from cooperative peers to propose a query routing approach called Inverted PeerCluster Index (IPI) that simulates the conventional inverted index of the centralised corpus to organise the statistics of peers’ terms. The results show a competitive retrieval quality in comparison to baseline approaches. Furthermore, I study the applicability of using the conventional Information Retrieval models as peer selection approaches where each peer can be considered as a big document of documents. The experimental evaluation shows comparative and significant results and explains that document retrieval methods are very effective for peer selection that brings back the analogy between documents and peers. Additionally, Learning to Rank (LtR) algorithms are exploited to build a learned classifier for peer ranking at the super-peer level. The experiments show significant results with state-of-the-art resource selection methods and competitive results to corresponding classification-based approaches. Finally, I propose reputation-based query routing approaches that exploit the idea of providing feedback on a specific item in the social community networks and manage it for future decision-making. The system monitors users’ behaviours when they click or download documents from the final ranked list as implicit feedback and mines the given information to build a reputation-based data structure. The data structure is used to score peers and then rank them for query routing. I conduct a set of experiments to cover various scenarios including noisy feedback information (i.e, providing positive feedback on non-relevant documents) to examine the robustness of reputation-based approaches. The empirical evaluation shows significant results in almost all measurement metrics with approximate improvement more than 56% compared to baseline approaches. Thus, based on the results, if one were to choose one technique, reputation-based approaches are clearly the natural choices which also can be deployed on any P2P network.
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Con el inicio del periodo Post-Guerra Fría el Sistema Internacional comienza a experimentar un incremento en el fortalecimiento de su componente social; la Sociedad de Estados alcanza un mayor nivel de homogenización, el estado, unidad predominante de esta, comienzan atravesar una serie de transformaciones que obedecerán a una serie de cambios y continuidades respecto al periodo anterior. Desde la perspectiva del Realismo Subalterno de las Relaciones Internacionales se destacan el proceso de construcción de estado e inserción al sistema como las variables que determinan el sentimiento de inseguridad experimentado por las elites estatales del Tercer Mundo; procesos que en el contexto de un nuevo y turbulento periodo en el sistema, tomara algunas características particulares que darán un sentido especifico al sentimiento de inseguridad y las acciones a través de las cuales las elites buscan disminuirlo. La dimensión externa del sentimiento de inseguridad, el nuevo papel que toma la resistencia popular como factor determinante del sentimiento de inseguridad y de la cooperación, así como del conflicto, entre los miembros de la Sociedad Internacional, la inserción como promotor de estrategias de construcción de Estado, son alguno de los temas puntuales, que desde la perspectiva subalterna, parecen salir a flote tras el análisis del sistema en lo que se ha considerado como el periodo Post-Guerra Fría. En este sentido Yemen, se muestra como un caso adecuado no solo para poner a prueba las postulados de la teoría subalterna, veinte años después de su obra más prominente (The third world security Predicament), escrita por M. Ayoob, sino como un caso pertinente que permite acercarse más a la comprensión del papel del Tercer Mundo al interior de la Sociedad Internacional de Estados.