Made available in DSpace on 2014-06-11T19:28:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-10-03Bitstream added on 2014-06-13T19:57:13Z : No. of bitstreams: 1 cruz_lr_me_mar.pdf: 1278685 bytes, checksum: 8afdc5f67f56b2ec7ff79b5b3f382e71 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A Internet propiciou a formação de uma rede descentralizada de informações nunca antes encontrada em nossa sociedade. Baseando-se na digitalização dos produtos culturais, a arquitetura da rede permitiu uma ampla distribuição de informações de maneira fácil e relativamente barata, favorecendo uma distribuição cultural de novo tipo, baseada na facilidade de apropriação, de compartilhamento e de produção de réplicas idênticas ao original. Contudo, essa prática tão comum da cibercultura freqüentemente desconsidera as leis de proteção dos direitos autorais, pois estimula uma livre circulação de informações em detrimento da proteção dos interesses autorais e mercadológicos de distribuição. A Internet inaugura ainda novos movimentos sociais, pautados pela construção comum de licenças autorais atualizadas e de práticas políticas de Desobediência Civil nesse novo terreno de disputa. Portanto, objetivamos neste trabalho investigar as formas de distribuição de informação no arcabouço tecnoinformacional e as suas relações com as estruturas jurídicas das leis proteção autoral e com as velhas e novas formas de acumulação. / The Internet made possible the beginning of a unique decentralized network of information in our society. Relied on the digitalization of cultural products, the net’s framing allowed a biggest sharing of information in a easier and cheaper way, supporting a cultural distribution of a new kind, based on the facilities of appropriation, sharing and production of identical copies from the original one. However, this ciberculture common practice frequently disrespect the copyright laws, because it encourage a free circulation of information in detriment of the authors and merchandising interests protection. The Internet still made possible the emerging of new social movements, ruled by common construction of actualized author’s licenses and by political actions of Civil Disobedience within this new space of conflict. Thus, our objective in this work is investigate the new paths of information sharing ways in the techno-informational structure and its relations with the juridical framing of the copyright and with the new and old ways of accumulation.

Context. Online piracy is widespread, controversial and poorly understood social phenomena that affects content creators, owners, and consumers. Online piracy, born from recent, rapid ITC changes, raises legal, ethical, and business challenges. Content owners, authors and content consumers should benefit from better understanding of online piracy. Improved, better adapted to marketplace and ITC changes content distribution models should benefit content owners and audiences.Objectives. Investigate online piracy effect on pirated product sales. Improve understanding of online piracy behaviors and process scale.Methods. This observational study investigated movie-sharing effect on U.S. box office. Movie sharing was observed over BitTorrent network, the most popular peer-to-peer file-sharing network. Relationship between piracy and sales was analyzed using linear regression model.Results. File sharing was found to have a slightly positive correlation with U.S. box office sales during first few weeks after film release, and no effect afterwards. Most of newly released movies are shared over BitTorrent network. File sharing is a global, massive phenomenon.Conclusions. I conclude that online movie file sharing has no negative correlation on U.S. box office. Slightly positive movie sharing correlation to box office sales could have occurred because sharing rather informs, than substitutes cinema going.

This study focuses on the proactive methods against illegal downloading. This study will look into the new implemented IPRED law that could be seen as one attempt to prevent the illegal downloading. Furthermore, this study investigates how new services such as Spotify can be a legal alternative to the illegal downloading and also how the music industry has handled the transition from CD sales to the new digital media.   Our research consists of both qualitative and quantitative study where a survey has been conducted among 50 people in Jönköping University. The study also consists of two interviews from experts within the field which gave the study more credibility.   We discovered through our research that the music industry has been going through four different phases and that the actual state the music industry is that they have started to accept the technology and adjust their business to it. We have also discovered through our survey that the IPRED law has had an impact in the fight against illegal downloading. The winner is Spotify that most users have turned to when the IPRED law was introduced.

In this comparative study based on experimentation it is demonstrated that the two evaluated machine learning techniques, Bayesian networks and random forests, have similar predictive power in the domain of classifying torrents on BitTorrent file sharing networks. This work was performed in two steps. First, a literature analysis was performed to gain insight into how the two techniques work and what types of attacks exist against BitTorrent file sharing networks. After the literature analysis, an experiment was performed to evaluate the accuracy of the two techniques. The results show no significant advantage of using one algorithm over the other when only considering accuracy. However, ease of use lies in Random forests’ favour because the technique requires little pre-processing of the data and still generates accurate results with few false positives.

In this comparative study based on experimentation it is demonstrated that the two evaluated machine learning techniques, Bayesian networks and random forests, have similar predictive power in the domain of classifying torrents on BitTorrent file sharing networks.This work was performed in two steps. First, a literature analysis was performed to gain insight into how the two techniques work and what types of attacks exist against BitTorrent file sharing networks. After the literature analysis, an experiment was performed to evaluate the accuracy of the two techniques.The results show no significant advantage of using one algorithm over the other when only considering accuracy. However, ease of use lies in Random forests’ favour because the technique requires little pre-processing of the data and still generates accurate results with few false positives.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme der Fakultaet fuer Informatik der TU Chemnitz. Anhand des Freenet-Projektes wird erklärt, wie anonymes Filesharing funktioniert. Der Vortrag beschreibt den Aufbau und die Funktion von Freenet und wie man Daten in Freenet einspielt bzw. wiederfinden kann. Es werden Vor und Nachteile von Freenet gegenüber anderen Projekten genannt.

This thesis contributes to the knowledge of how computer-mediated communication and information sharing works in large groups and networks. In more detail, the research question put forward is: in large sharing networks, what concerns do end-users have regarding to whom to provide material? A theoretical framework of gift-giving was applied to identify, label and classify qualitative end-user concerns with provision. The data collection was performed through online ethnographical research methods in two large sharing networks, one music-oriented and one photo-oriented. The methods included forum message elicitation, online interviews, application use and observation. The result of the data collection was a total of 1360 relevant forum messages. A part from this there are also 27 informal interview logs, field notes and samples of user profiles and sharing policies. The qualitative analysis led up to a model of relationships based on the observation that many users experienced conflicts of interest between various groups of receivers and that these conflicts, or social dilemmas, evoked concerns regarding public and non-public provision of material. The groups of potential recipients were often at different relationship levels. The levels ranged from the individual (ego), to the small group of close peers (micro), to a larger network of acquaintances (meso) to the anonymous larger network (macro). It is argued that an important focal point for analysis of cooperation and conflict is situated in the relations between these levels. Deepened studies and analysis also revealed needs to address dynamic recipient groupings, the need to control the level of publicness of both digital material and its metadata (tags, contacts, comments and links to other networks) and that users often refrained from providing material unless they felt able to control its direction. A central conclusion is that public and non-public gifting need to co-emerge in large sharing networks and that non-public gifting might be an important factor for the support of continued provision of goods in sustainable networks and communities.

DOGMA is a resource management system designed to create a supercomputer like system from unused desktop computers. Scalability is one of the challenges faced by DOGMA because it uses a strict client/server architecture. Distributing large files over a client server architecture is problematic since available network bandwidth is limited. The Local URL Resolution Protocol(LURP) addresses this problem for environments where there are high node densities. LURP implements a locality aware Peer-to-Peer file distribution model to increase the speed of file distribution while reducing the overall network congestion.

Peer to Peer (P2P) models are based on user altruism, wherein a user shares its content with other users in the pool and it also has an interest in the content of the other nodes. Most P2P systems in their current form are not fair in terms of the content served by a peer and the service obtained from swarm. Most systems suffer from free rider's problem where many high uplink capacity peers contribute much more than they should while many others get a free ride for downloading the content. This leaves high capacity nodes with very little or no motivation to contribute. Many times such resourceful nodes exit the swarm or don't even participate. The whole scenario is unfavorable and disappointing for P2P networks in general, where participation is a must and a very important feature. As the number of users increases in the swarm, the swarm becomes robust and scalable. Other important issues in the present day P2P system are below optimal Quality of Service (QoS) in terms of download time, end-to-end latency and jitter rate, uplink utilization, excessive cross ISP traffic, security and cheating threats etc. These current day problems in P2P networks serve as a motivation for present work. To this end, we present an efficient data distribution framework in Peer-to-Peer (P2P) networks for media streaming and file sharing domain. The experiments with our model, an alliance based peering scheme for media streaming, show that such a scheme distributes data to the swarm members in a near-optimal way. Alliances are small groups of nodes that share data and other vital information for symbiotic association. We show that alliance formation is a loosely coupled and an effective way to organize the peers and our model maps to a small world network, which form efficient overlay structures and are robust to network perturbations such as churn. We present a comparative simulation based study of our model with CoolStreaming/DONet (a popular model) and present a quantitative performance evaluation. Simulation results show that our model scales well under varying workloads and conditions, delivers near optimal levels of QoS, reduces cross ISP traffic considerably and for most cases, performs at par or even better than Cool-Streaming/DONet. In the next phase of our work, we focussed on BitTorrent P2P model as it the most widely used file sharing protocol. Many studies in academia and industry have shown that though BitTorrent scales very well but is far from optimal in terms of fairness to end users, download time and uplink utilization. Furthermore, random peering and data distribution in such model lead to suboptimal performance. Lately, new breed of BitTorrent clients like BitTyrant have shown successful strategic attacks against BitTorrent. Strategic peers configure the BitTorrent client software such that for very less or no contribution, they can obtain good download speeds. Such strategic nodes exploit the altruism in the swarm and consume resources at the expense of other honest nodes and create an unfair swarm. More unfairness is generated in the swarm with the presence of heterogeneous bandwidth nodes. We investigate and propose a new token-based anti-strategic policy that could be used in BitTorrent to minimize the free-riding by strategic clients. We also proposed other policies against strategic attacks that include using a smart tracker that denies the request of strategic clients for peer listmultiple times, and black listing the non-behaving nodes that do not follow the protocol policies. These policies help to stop the strategic behavior of peers to a large extent and improve overall system performance. We also quantify and validate the benefits of using bandwidth peer matching policy. Our simulations results show that with the above proposed changes, uplink utilization and mean download time in BitTorrent network improves considerably. It leaves strategic clients with little or no incentive to behave greedily. This reduces free riding and creates fairer swarm with very little computational overhead. Finally, we show that our model is self healing model where user behavior changes from selfish to altruistic in the presence of the aforementioned policies.

Security is essential to communication between entities in the internet. Delay tolerant and disconnected Mobile Ad Hoc Networks (MANET) are a class of networks characterized by high end-to-end path latency and frequent end-to-end disconnections and are often termed as challenged networks. In these networks nodes are sparsely populated and without the existence of a central server, acquiring global information is difficult and impractical if not impossible and therefore traditional security schemes proposed for MANETs cannot be applied. This thesis reports trust management schemes for peer to peer (P2P) application in delay tolerant disconnected MANETs. Properties of a profile based file sharing application are analyzed and a framework for structured P2P overlay over delay tolerant disconnected MANETs is proposed. The framework is implemented and tested on J2ME based smart phones using Bluetooth communication protocol. A light weight Content Driven Data Propagation Protocol (CDDPP) for content based data delivery in MANETs is presented. The CDDPP implements a user profile based content driven P2P file sharing application in disconnected MANETs. The CDDPP protocol is further enhanced by proposing an adaptive opportunistic multihop content based routing protocol (ORP). ORP protocol considers the store-carry-forward paradigm for multi-hop packet delivery in delay tolerant MANETs and allows multi-casting to selected number of nodes. Performance of ORP is compared with a similar autonomous gossiping (A/G) protocol using simulations. This work also presents a framework for trust management based on dynamicity aware graph re-labelling system (DA-GRS) for trust management in mobile P2P applications. The DA-GRS uses a distributed algorithm to identify trustworthy nodes and generate trustable groups while isolating misleading or untrustworthy nodes. Several simulations in various environment settings show the effectiveness of the proposed framework in creating trust based communities. This work also extends the FIRE distributed trust model for MANET applications by incorporating witness based interactions for acquiring trust ratings. A witness graph building mechanism in FIRE+ is provided with several trust building policies to identify malicious nodes and detect collusive behaviour in nodes. This technique not only allows trust computation based on witness trust ratings but also provides protection against a collusion attack. Finally, M-trust, a light weight trust management scheme based on FIRE+ trust model is presented.