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The Peer-to-Peer (P2P) architecture has been successfully used to reduce costs and increase the scalability of Internet live streaming systems. However, the effectiveness of these applications depends largely on user (peer) cooperation. In this article we use data collected from SopCast, a popular P2P live application, to show that there is high correlation between peer centrality-out-degree, out-closeness, and betweenness-in the P2P overlay graph and peer cooperation. We use this finding to propose a new regression-based model to predict peer cooperation from its past centrality. Our model takes only peer out-degrees as input, as out-degree has the strongest correlation with peer cooperation. Our evaluation shows that our model has good accuracy and does not need to be trained too often (e.g., once each 16 min). We also use our model to sketch a mechanism to detect malicious peers that report artificially inflated cooperation aiming at, for example, receiving better quality of service. [ABSTRACT FROM AUTHOR]

The article examines the consequences of the decision of the Federal Court of Australia in the case 'Dallas Buyers Club LLC v iiNet Ltd.' that revived the prospect of legal claims against the users of BitTorrent, a communications protocol of peer-to-peer online file sharing.

The article reports on the Irish High Court's decision to use graduated response system (GRS) in dealing with the problem of unauthorized peer-to-peer (P2P) file-sharing of sound recordings on the Internet and discusses other court cases dealing with Internet Service providers and common law GRS.

This paper presents a novel fountain code-based hybrid P2P and cloud storage system. While most cloud storage systems guarantees data retrievability of high level, they may be vulnerable to data privacy since the stored data may be exposed to others by accident or design. On the other hand, P2P storage system keeps any peer from accessing the whole data by dividing the data into small pieces and distributing them to multiple participating peers, but may degrade data retrievability due to unstable peers. The proposed hybrid storage system attempts to enhance data retrievability and privacy by effectively distributing fountain encoded symbols to cloud server system and participating peers. It is demonstrated that the proposed hybrid storage system achieves the desired level of data retrievability with a short upload time, and enhance privacy by preventing others from reading the contents. [ABSTRACT FROM AUTHOR]

Dealing with the churn problem is an important requirement in distributed systems in general and more precisely in structured peer-to-peer overlay networks due to their dynamicity. This problem refers to the change in the set of participating nodes due to the frequent joins, leaves or failures. Such variations induce at worst the loss of objects and at least performance degradation. This is due to the reorganization of the set of replicas of the affected objects. Till now, this problem has been mostly addressed at the p2p routing level to ensure the reach ability of peers by maintaining the consistency of the logical neighbors. However, the main challenge for structured p2p systems is to protect the ability of the system to locate any present object. At the storage level, avoiding data losses is still an issue when a reconfiguration of the participant peers occurs. In this paper and after presenting first the existing replication techniques, we propose the zone replication technique used in both Chord and Kademlia protocols in order to attenuate churn effects. Finally, we point out some ways that can lead to better and maybe robust replication protocols. [ABSTRACT FROM AUTHOR]

Due to limited radio range and mobility of nodes in mobile ad hoc networks (MANETs), the network partitioning and merging could occur frequently. When structured peer-to-peer (P2P) overlays are running over MANETs, then network partition in the physical network can also cause network partition at the overlay layer. Existing approaches for structured P2P overlay over MANETs do not detect network partition at the overlay layer. This paper proposes a cross-layer approach to detect network partition at the overlay layer for structured P2P overlay over MANETs. Simulation results show that the proposed approach is highly effective and efficient in terms of routing overhead, success ratio and false-negative ratio. [ABSTRACT FROM AUTHOR]

This study examines the impact of peer-to-peer (P2P) file sharing on the Australian theatrical film industry. Using a large data set of torrent downloads observed on three popular P2P networks, we find evidence of a sales displacement effect on box office revenues. However, although statistically significant, the economic significance of this displacement appears relatively small. To establish causality, we make use of the state-day-level panel data structure permitting the use of film fixed effects to help mitigate the endogeneity between film revenues and downloads. To further assist identification, we propose a downloading cost function that considers other states' downloading activities as a proxy for the number of peers in the download swarm; the US DVD release date as a supply shock to P2P networks; and the substantial structural progression within the Australian internet service provision industry that occurred over the sample period. We observe that the release gap between the US and Australian markets is a key contributor to piracy early in a film's theatrical life. This finding provides a partial explanation for the industry's move towards coordinated worldwide releases. [ABSTRACT FROM AUTHOR]

The sharing economy converges around activities facilitated through digital platforms that enable peer-to-peer access to goods and services. It constitutes an apparent paradox, framed as both part of the capitalist economy and as an alternative. This duplicity necessitates focusing on the performances of the sharing economy: how it simultaneously constructs diverse economic activities whilst also inviting the deconstruction of ongoing practices of dominance. Such performances hold open the question of what the (sharing) economy is, suspending it as a space for both opportunity and critique. Drawing on participant observation at a sharing economy ‘festival’ and analysis of the vocabularies of online platforms, the paper outlines three performances of sharing through community, access and collaboration. It argues through these performances that the sharing economy is contingent and complexly articulated. It has the potential to both shake up and further entrench ‘business-as-usual’ through the ongoing reconfiguration of a divergent range of (economic) activities. Whilst offering an antidote to the narrative of economy as engendering isolation and separation, the sharing economy simultaneously masks new forms of inequality and polarisations of ownership. Nonetheless, the paper concludes in suggesting that by pointing to wider questions concerning participation in, access to and production of resources, the sharing economy should not be dismissed. Instead, it should serve as prompt to engage with ‘digital’ transformations of economy in the spirit of affirmative critique that might enact the promise of doing economy differently. [ABSTRACT FROM AUTHOR]

Social media data are increasingly being used in disaster management for information dissemination, establishment of situational awareness of the 'big picture' of the disaster impact and emerged incidences over time, and public peer-to-peer backchannel communications. Before we can fully trust the situational awareness established from social media data, we need to ask whether there are biases in data generation: Can we simply associate more tweets with more severe disaster impacts and therefore higher needs for relief and assistance in that area? If we rely on social media for real-time information dissemination, who can we reach and who has been left out? Due to the uneven access to social media and heterogeneous motivations in social media usage, situational awareness based on social media data may not reveal the true picture. In this study, we examine the spatial heterogeneity in the generation of tweets after a major disaster. We developed a novel model to explain the number of tweets by mass, material, access, and motivation (MMAM). Empirical analysis of tweets about Hurricane Sandy in New York City largely confirmed the MMAM model. We also found that community socioeconomic factors are more important than population size and damage levels in predicting disaster-related tweets. [ABSTRACT FROM AUTHOR]

Recently P2P networks and theirs applications have become increasingly popular. On the other hand, considering ever increasing industrial and scholarly popularity of Vehicular Ad hoc Networks (VANETs), implementation P2P network over VANET has attracted attentions recently. One of the most important applications in P2P networks is content discovery. Regarding the difficulties of structured and unstructured protocols over VANET, this paper presents a new framework for sharing and content discovery which formed a structured overlay to overcome problems likes broadcasting storm which is the main problem of unstructured methods. On the other hand, this paper tries to solve the instability of structured overlay networks as the main problem of them, by applying geographical and semantic partitioning. Simulation results clarified higher performance of proposed framework in comparison to previous protocols. Furthermore, applying G-Network queue network, we have modeled the behavior of proposed framework and then, optimize it by gradient descent optimization method. [ABSTRACT FROM AUTHOR]

This text is a summary of my dissertation where I try to show some key points of the study. I chose to discuss very concisely the motivations that have led me to conduct the study in Bulgaria but also my methodological inspiration and the fieldwork I have done. Here, I also introduce the three main actors in the network of relations, constructed as a result of the ethnographic study: Internet Providers, Torrents Trackers and Subtitling pages. [ABSTRACT FROM AUTHOR]

This study examines how a file sharing system affects its users’ sense of community (SOC). It was expected that the file sharing system would increase members’ knowledge about and participation in the file sharing network which, in turn, would increase their SOC. The aim of this study was to identify the barriers that hinder community building in file sharing networks, by examining how use of a specific network – Direct Connect++ (DC++) – affects its users’ SOC. It was our hypothesis and expectation that extended use of file sharing system would increase members’ knowledge about, and participation in, the file sharing network, and this in turn would increase their SOC. However, although DC++ was found to have a number of properties that coincide with the theories of SOC, two barriers were found that hindered DC++ from working as a genuine community. These barriers were related to anonymity and elitism among community members. The findings challenge previous idealistic theories about the development of an SOC but nonetheless demonstrate the positive effects of network membership. [ABSTRACT FROM AUTHOR]

Combining ontologies in expressive fragments of Description Logics in inherently distributed peer-to-peer settings with autonomous peers is still a challenge in the general case. Although several modular ontology representation frameworks have been proposed for combining Description Logics knowledge bases, each of them has its own strengths and limitations. In this paper, we consider networks of peers, where each peer holds its own ontology within the $${\mathcal {SHIQ}}$$ fragment of Description Logics, and subjective beliefs on how its knowledge can be coupled with the knowledge of others. To allow peers to reason jointly with their coupled knowledge, while preserving their autonomy on evolving their knowledge, data, and subjective beliefs, we propose the $$E\text {-}{\mathcal {SHIQ}}$$ representation framework. The article motivates the need for $$E\text {-}{\mathcal {SHIQ}}$$ and compares it to existing representation frameworks for modular Description Logics. It discusses the implementation of the $$E\text {-}{\mathcal {SHIQ}}$$ distributed reasoner and presents experimental results on the efficiency of this reasoner. [ABSTRACT FROM AUTHOR]

The state of art authentication schemes are tightly linked with encryption or crypto systems, which provides concrete foundations to move towards the concept of access control by confirming the user identity. However the openness of the computer network makes the identity credentials vulnerable even transmitted as cipher text especially in lots of peer-to-peer (P2P) networks. The malicious attackers can possibly steal and fake the user identity by eavesdropping, hijacking, cryptanalysis and forging. In this paper, a novel identity authentication mechanism is proposed based on the reverse usage of the Network Covert Channel (NCC) which is originally designed by attackers to create stealth communication. Different from NCC, where the packet intervals can be exploited as the data carrier to transmit the unauthorized information, we exploit such capability in Network-Covert-Channel-based Identity Authentication (NCCIA) to transmit the identity tag. By validating user identity in a covert manner, we provide a more secure authentication method compared with many existing approaches. A NCCIA demo system is designed on a FTP Platform to verify our method. The experiments demonstrate the NCCIA can prevent the attackers from eavesdropping while maintaining transmission efficiency. [ABSTRACT FROM AUTHOR]

Peer-to-Peer (P2P) technology has experienced its great popularity for resource sharing in current network services. However, lacking of prior experience and knowledge about other peers' reputation, P2P suffer from malicious behaviors launched by malicious peers. Developing effective strategies to establish trust model for the P2P system is a good way to address this problem. In this paper, we propose a novel topological potential weighted community-based recommendation trust (TPCommuTrust) model architecture, which is based on topological potential weighted community credential to score and rate peers' previous data transactions. Contributed by topological potential, which characterizes repercussion effect between peers, the reputation model of the peers is created. The unique and efficient mechanism is proposed to perform data transaction based on credentials intra and inter-community. Moreover, how TPCommuTrust can provide an access control against malicious peers is illustrated as well. Simulation results show that TPCommuTrust model is robust and highly efficient to identify malicious nodes. [ABSTRACT FROM AUTHOR]

Peer-to-peer relay technique provides the opportunity of cooperative communication between users to achieve the transmission diversity. In this paper, the problem of relay selection and subcarrier allocation in peer-to-peer cooperative OFDMA system with channel distribution uncertainty is studied. The quality of service (QoS) requirements are characterized with the probabilistic constraints. The Kullback-Leibler (KL) divergence is adopted to describe the uncertainty of the channel state information (CSI), which follows a distribution deviated within a certain distance from the reference distribution. Since the probabilistic constraint is intractable, we resort to a tractable upper bound instead. The problem is solved by the interior point cutting plane (IPCP) method, which proceeds in round whereby an iterative method is designed to combine both golden section method and interior point method to find the saddle point of the constraint. Simulation results show the effectiveness of our algorithm. [ABSTRACT FROM AUTHOR]

P2P file-sharing systems have been suffering from file unavailability or poor download speed due to lack of enough seeds. To download rare files, users are typically forced to keep their desktops online for a long time, which is undesirable for most users. To get over this, several commercial P2P systems launched offline download service, also known as cloud download, which employs stable and high-capacity servers to take over users' download tasks, and thus users do not need to stay online all the time. This paper focuses on characterizing the performance of offline download, including the overall performance provision and the expected performance of individual download tasks. Through model characterization and experimental verification based on real-world trace, we are the first to confirm the feasibility and effectiveness of offline download for a large spectrum of P2P systems: over 90 % files can be successfully retrieved, and most of the downloads only take a few days. Furthermore, we disclose that the completion time of offline download is extremely volatile, and thus develop a method to accurately predict the expected performance of individual downloads. An instance of applying the prediction results is also presented to save the server-side bandwidth. Finally, we implement a prototype of offline download service, release it in a real P2P network, and present our work experience with it. [ABSTRACT FROM AUTHOR]

A network coding based peer-to-peer (P2P) file sharing system has been proposed in recent years. It uses the random combination of encoded pieces to make the file sharing more effective. Most of the conventional P2P file sharing systems adopt a random (or rarest piece first) transmission policy to avoid too many duplicated pieces and rare pieces occurring in the network. Network coding can simply solve this problem. However, some of the studies show that network coding brings the overhead of coding/decoding delay and message overhead; after all, the performance of network coding is not better than other schemes that are without network coding. Therefore, we propose a network coding based file sharing system over unstructured P2P networks considering the overhead from the network coding. We make comparisons with other schemes without network coding. Our simulation results show that the proposed network coding based file sharing system is better than others, when the network coding scheme and non-network coding scheme adopt the same network environment even though the network coding is executed under a limited computation resource. [ABSTRACT FROM AUTHOR]

In peer-to-peer file sharing systems, file replication helps to avoid overloading file owners and improve file query efficiency. There exists a tradeoff between minimizing the number of replicas (i.e., replication overhead) and maximizing the replica hit rate (which reduces file querying latency). More replicas lead to increased replication overhead and higher replica hit rates and vice versa. An ideal replication method should generate a low overhead burden to the system while providing low query latency to the users. However, previous replication methods either achieve high hit rates at the cost of many replicas or produce low hit rates. To reduce replicas while guaranteeing high hit rate, this paper presents SWARM, a file replication mechanism based on swarm intelligence. Recognizing the power of collective behaviors, SWARM identifies node swarms with common node interests and close proximity. Unlike most earlier methods, SWARM determines the placement of a file replica based on the accumulated query rates of nodes in a swarm rather than a single node. Replicas are shared by the nodes in a swarm, leading to fewer replicas and high querying efficiency. In addition, SWARM has a novel consistency maintenance algorithm that propagates an update message between proximity-close nodes in a tree fashion from the top to the bottom. Experimental results from the real-world PlanetLab testbed and the PeerSim simulator demonstrate the effectiveness of the SWARM mechanism in comparison with other file replication and consistency maintenance methods. SWARM can reduce querying latency by 40-58 percent, reduce the number of replicas by 39-76 percent, and achieves more than 84 percent higher hit rates compared to previous methods. It also can reduce the consistency maintenance overhead by 49-99 percent compared to previous consistency maintenance methods. [ABSTRACT FROM AUTHOR]

Motivated by application in BitTorrent-like Peer-to-Peer resource sharing system, we introduce the maximization and minimization semi-latticized fuzzy relation geometric programming problems with max-min composition in this paper. The objective function in the proposed problem in nonlinear and the feasible domain is non-convex. The maximization problem is converted into a fuzzy relation monomial geometric programming and then solved. However, this approach is not effective for the minimization one. The linear programming method is applied to deal with the minimization problem. A step-to-step algorithm is develop to carried out the linear programming method and tow illustrative examples are provided at last. [ABSTRACT FROM AUTHOR]

The author argues that three-dimensional printing will test the success of American patent law's ability to promote innovation as of 2015. Patent-related grief is addressed in relation to the five stages of grief that are examined in the 1969 book "On Death and Dying: What the Dying Have to Teach Doctors, Nurses, Clergy & Their Own Families" by Elisabeth Kübler-Ross. Intellectual property and copyright laws in the U.S. are examined, along with peer-to-peer file sharing issues.

This paper re-examines data from a survey commissioned by Industry Canada on the effects of internet peer-to-peer (P2P) file sharing activities on music purchasing behaviour. The survey was designed to 'inform Industry Canada's policy development work' (Quote from project Description from Industry Canada's website at downloaded 23 January 2012) and the need for copyright law reform in Canada in light of the technological innovation posed by P2P file sharing. The Journal of Evolutionary Economics published a study of the Industry Canada data by Andersen and Frenz (AF) in 2010 which claimed to show '... no association between the number of P2P files downloaded and CD album sales (Andersen and Frenz 2010 ibid p 374),' and '... that P2P file-sharing is not to blame for the decline in CD markets. Music markets are not simply undermined by free music downloading and P2P file-sharing (Ibid p375).' Our paper corrects a number of fundamental errors in this analysis of AF, in particular the fact AF biased their results by excluding from their analysis the group of consumers who had completely stopped purchasing CDs (potentially because of P2P activity) prior to 2005. This is the very group who were most responsive, or likely to have substituted P2P downloading for CD purchases. We use longitudinal analysis of how reported changes in P2P downloading by individuals related to their reported changes in CD demand between 2004 and 2005 to better test the hypothesis of whether P2P downloading may reduce CD demand. Contrary to AF's results we find negative and generally statistically significant partial correlations between CD purchases and P2P downloads under a number of specifications and sample definitions. The range of these estimated correlations is between −0.047 and −0.061. This implies that a 10 % growth in P2P downloads is associated with between a 0.47 and 0.61 % decline in CD purchases. Our estimated relationships between CD sales and P2P downloads are broadly consistent with market sales data up to the time of the Industry Canada survey, unlike AF. [ABSTRACT FROM AUTHOR]

Current reputation systems for peer-to-peer (P2P) file sharing networks suffer from high overhead on reputation querying. Also, purely relying on a threshold to detect malicious nodes may make a high-reputed node be reluctant to further increase its reputation in these reputation systems. On the other side, the social network concept of ”friendship foster cooperation” can be utilized to alleviate the high overhead in reputation systems. However, the limited number of friends limits the availability of file resources in these approaches. To overcome the drawbacks, we propose a social network based reputation system, namely SocialTrust, that synergistically leverages the social network connections and traditional credit based reputation system to provide efficient reputation management for P2P file sharing. In SocialTrust, each node favors friends for service transactions, which are resulted from both real life acquaintances and online partnerships established between high-reputed and frequently-interacted nodes. When no friends are available for a request, a node chooses the server with the highest reputation. The benefits of friendship and partnership on file sharing and cost saving encourage nodes to be continuously cooperative. Further, SocialTrust considers the number of friends/partners and the reputation of a node in reputation rewarding/punishment in order to realize accurate reputation evaluation. SocialTrust can also prevent certain attacks such as deny of service and collusion. Extensive trace-driven simulation demonstrates the effectiveness of SocialTrust. [ABSTRACT FROM AUTHOR]

Author's rights and copyright law have gone through quite a few changes in the 'post-print' culture of binary systems, digital formations and techno-practices. Technological development supports a new concept of author's rights by promoting a free internet and digital market, as well as new contemporary experience of culture that is rooted in digital technology, mass communication and the world of multimedia and virtuality. Though computer and digital technology have served both authors and users in various ways, they have also served as a very fertile ground for sharing copyrighted content, thus leading to numerous copyright infringements and conflicts with the copyright law. The aim of this paper is to identify and analyze the ways in which computer and digital technology have given rise to new trends in the production (e.g. remix culture) and consumption (e.g. peer-to-peer file sharing technology) of culture, but also to determine how new forms of distribution, use and sharing of digital content changed and shaped the perception of authorship in the 21st century. In order to analyze the dynamic, nature and structure by which new digital and networking technologies are affecting the concept of authorship and author's rights and to test the consistency of previously established hypotheses, we conducted a survey amongst the general public. 535 questionnaires were completed. Data was analyzed using SPSS tool and a quantitative method of analysis. In the analysis special attention was given to both, the concept of authorship in the digital environment and the concept of peer-to-peer file sharing technology as not so new, but still very popular networked architecture for distributing, using and sharing digital content. Results have shown that most of the respondents use peer-to-peer file sharing technology to access, consume and/or share different cultural content (e.g. movies, music, books, etc.) while violating the rights of copyright holders. That is one of the main reasons why copyright holders and creative industry constantly finds new ways to fight peer-to-peer networking technology, especially commercial file sharing, thus sometimes restraining cultural production and even technological development. This leads to the conclusion that this new dynamic, decentralized and distributed networked environment grounded in digital democracy and participating culture of prosumers asks for new legal initiatives and solutions. The research shows that the basic understanding of authorship and the rights of authors and other creative workers in the context of Internet culture and digital media has not changed a lot, but due to new available digital means of production and tools of consumption, users' attitudes, habits and practices towards them have. To resolve this conflict, the law needs to find new mechanisms to establish the balance between the needs and rights of both authors and users. [ABSTRACT FROM AUTHOR]

The article reports on peer-to-peer (P2P) file sharing in the U.S. It mentions its involvement in user rights activism, international law and digital rights management (DRM). An overview of the Digital Millennium Copyright Act (DMCA), Anti-Counterfeiting Trade Agreement (ACTA) and the case A&M Records Inc. v. Napster Inc. is also presented.

It is a very difficult task to estimate abnormal objects and analyze reliability in peer-to-peer (P2P) networks. In the P2P network environment, successful execution of a program is conditional on the successful access of related files and software distributed throughout the P2P network. Abnormal phenomena in peer-to-peer systems occur very often. They occur in software and in data operated on by the computer itself or by a connected computer. This paper focuses on estimating abnormal objects and reliability in a P2P network that is very complex and different. We propose an estimation method for abnormal objects and reliability in a P2P network. First, we define a P2P static graph model, where the node is a computational unit and the edge is a communication unit in the P2P network. The computational unit is software or data installed on a computer. Second, we propose a converting algorithm where the P2P static graph model is converted to a colored Petri net model. Last, we estimate abnormal objects and the reliability of the P2P network. The technique successfully classifies abnormal objects and estimates reliability of the P2P network. This procedure provides a very useful method for detection of abnormal objects in a P2P network, which occur through abnormal faults of software and data. While we manage the P2P network, the reliability of the system can be predicted. [ABSTRACT FROM AUTHOR]

Online Peer-to-Peer (P2P) lending marketplaces allow individuals to lend and borrow directly among each other without the mediation of a creditor bank institution. Prior literature has examined online P2P, but has largely been limited to the Western context. This paper thus explores how social capital and other factors influences online P2P lending in the U.S. and China. Based on the archival data of Prosper and PPDai, we compare market outcome of two online P2P lending marketplaces in the U.S. and China. The empirical results show that social capital is not equally important in different online communities. Social capital seems to be more influential for likelihood of getting funded in China than in the U.S. In contrast, social capital has influence on interest rate in the U.S. only. The authors' study thus extends current understanding about how social capital influences online communities to a global perspective. [ABSTRACT FROM AUTHOR]

Multi-level linear programming problem subject to addition-min fuzzy relation inequalities is introduced to characterize a kind of optimization models in BitTorrent-like Peer-to-Peer file sharing systems. Based on some theorems, which contribute to the resolution of the proposed problem, we develop a novel algorithm to find the unique optimal solution. A practical application example is presented to illustrate the feasibility and efficiency of the algorithm. [ABSTRACT FROM AUTHOR]

The paper investigates theoretical issues in applying the universal swarming technique to efficient content distribution. In a swarming session, a file is distributed to all the receivers by having all the nodes in the session exchange file chunks. By universal swarming, not only all the nodes in the session, but also some nodes outside the session may participate in the chunk exchange to improve the distribution performance. We present a universal swarming model where the chunks are distributed along different Steiner trees rooted at the source and covering all the receivers. We assume chunks arrive dynamically at the sources and focus on finding stable universal swarming algorithms. To achieve the throughput region, universal swarming usually involves a tree-selection subproblem of finding a min-cost Steiner tree, which is NP-hard. We propose a universal swarming scheme that employs an approximate tree-selection algorithm. We show that it achieves network stability for a reduced throughput region, where the reduction ratio is no more than the approximation ratio of the tree-selection algorithm. We propose a second universal swarming scheme that employs a randomized tree-selection algorithm. It achieves the throughput region, but with a weaker stability result. Comprehensive simulation results support the stability analysis of the algorithms. The proposed schemes and their variants are expected to be useful for infrastructure-based content distribution networks with massive content and relatively stable network environment. [ABSTRACT FROM AUTHOR]

The article discusses issues associated with the advent of technological advancements and new forms of media. Topics discussed include deterrence of copyright infringement, need for preventing Internet users' access to peer-to-peer ("P2P") file-sharing, and the role of Copyright Alert System in it.

Peer-to-peer (P2P) overlay networks are widely employed in distributed systems. Furthermore, the number of hops required by a node for searching an object is the fundamental search cost of a P2P network. Hence, since placing replicas can efficiently reduce such a cost of the whole system, how to deploy replicas to reduce it as much as possible becomes a critical problem of P2P networks. In this study, the authors investigate this centre problem for the randomised P2P network 'Symphony'. Particularly, the authors present a stochastic analysis on optimal replica placements, in terms of number of total hops, as well as proposing an optimal replica placement algorithm to perform a simulation study on this issue. Both the theoretical and experimental results show that locations of optimal replica placements in Symphony are not necessarily closest to the target node in the identifier space. Hence, based on the results, the authors evaluate one existing simple but experimentally efficient replica placement strategy, which exactly allocates replicas at nodes closest to the target node, to provide some guidelines on designing more efficient strategy applicable to the real-world Symphony. [ABSTRACT FROM AUTHOR]

The use of peer-to-peer (P2P) networks for multimedia distribution has spread out globally in recent years. The mass popularity is primarily driven by efficient distribution of content, also giving rise to piracy. An end user (buyer) of a P2P content distribution system does not want to reveal his/her identity during a transaction with a content owner (merchant), whereas the merchant does not want the buyer to further distribute the content illegally. Therefore, there is a strong need for a content distribution mechanism over P2P networks that do not pose security and privacy threats to the copyright holders and end users, respectively. The existent systems for copyright and privacy protection employ cryptographic mechanisms at a cost of high computational burden which makes these systems impractical to distribute large sized files, such as music albums or movies. In this paper, we propose and analyze a P2P content distribution system which allows efficient distribution of large-sized content while preserving the security and privacy of merchants and buyers, respectively. Our proposed framework is able to resolve the problems of piracy tracing, buyer frameproofness, collusion resistance, dispute resolution and buyer’s anonymity. We have carried out simulations to evaluate the performance of our framework in terms of imperceptibility, robustness, throughput and content delivery costs. The experimental results confirm that the proposed framework provides an efficient solution to copyright infringement issues over P2P networks, reducing the multimedia file sizes as much as five times on average, while protecting the end users’ privacy and anonymity. [ABSTRACT FROM AUTHOR]

Kim Dotcom, founder of Megaupload Limited, has been in many news headlines over the past year. Megaupload--one of Dotcom's many peer-to-peer sharing sites--was the center of controversy, as it allowed users to upload and share all sorts of files, including copyrighted material. After an organized effort by the Department of Justice and several foreign governments, Dotcom was arrested for (secondary) copyright infringement and his site was ultimately shut down. Dotcom has recently launched a new service, MEGA, which he claims will evade copyright laws entirely. Like other well-known cloud-sharing services such as Dropbox and Google Drive, MEGA allows users to upload files and to share them with select users. In an attempt to avoid liability, MEGA locally encrypts all files on the user's computer before they are uploaded to the site. The private key and public key used to encrypt and decrypt the file are retained solely by the user; MEGA gets no part of that information. This, Dotcom argues, will shift the entirety of the copyright onus to the user. This Issue Brief analyzes the protections afforded cyberlocker services like MEGA by the DMCA, including tensions raised in actual litigation. This Issue Brief argues that, while an ex ante secondary-liability analysis is difficult due to its contextual nature, MEGA's use of user-controlled encryption (UCE), deduplication, and distributed host servers may lend to an affirmative finding of liability. [ABSTRACT FROM AUTHOR]

In this paper, we provide an analytical model for the performance study of different structured P2P overlay networks used for lookup service in IP telephony systems. The overlay provides an infrastructure for the lookup service required before an actual voice communication is initiated. Our model captures the performance behavior of such overlays including the mean session set-up delay of a call as well as the system capacity. These parameters reflect how good an IP telephony overlay is performing. We formulate the system as a queuing network. We idealize Chord routing semantics to extract useful observations to obtain closed form expressions for the session setup delay and capacity as a function of the number of participating supernodes (SN). The analysis also answers the question of finding an optimum number of SN for minimum session setup delay. [ABSTRACT FROM AUTHOR]

The article discusses what the author refers to as a deficiency in the U.S. Federal Rules of Civil Procedure regarding the BitTorrent computer network protocol and copyright trolls which are law firms, attorneys, and other organizations that acquire the copyrights of particular works such as films and then file lawsuits against copyright infringing Internet users. Legal settlements and extortion are examined, along with the legal aspects of peer-to-peer technology and file transfers.

The article discusses the opportunities for musicians despite the harm they received due to advanced digital distribution and peer-to-peer (P2P) services. Topics discussed include proclamations made by the Recording Industry Association of America (RIAA) on illegal downloading of music, role of technology in making musicians able to participate in creation, development, and marketing process of music, and use of technology in creation and distribution of the music.

In this paper, we model the number of seeders during the initial stage of a file sharing process on BitTorrent networks. The initial stage is crucial for successfully identifying the initial seeder, who provided the source of the files on the Internet. Most existing BT models focus on different parameters in the steady state, which occurs at a later stage of a file sharing process. None of them are able to characterize the initial stage. In this study, we propose the first model on capturing the characteristics on the growth of the number of seeders during the initial stage on a BT network. Also, we derive a lower bound for the appearing time of the second seeder and the length of the stationary period. Our model suggests that the number of seeders remain stationary during the starting period of a file sharing process. When it enters the rapid-rising period, it increases more speedily as an increasing number of seeders are available for supplying the rarest pieces. The observed demarcation of the stationary period and the rapid-rising period is significant in identifying the initial seeder on a BT network. If the investigative work can be commenced within the stationary period, the chance of identifying the initial seeder is much higher. On the other hand, if the file distribution has entered the rapid-rising period, one can no longer determine which of the existing seeders is, indeed, the initial seeder. [ABSTRACT FROM AUTHOR]

Private BitTorrent community, known as 'BitTorrent Darknet' or 'Private Tracker (PT)', has received much attention in the research literature recently. Different from public BitTorrent community, PT can only be accessed by its registered members, and it can provide ultra-high downloading speed due to its effective Sharing Ratio Enforcement (SRE) incentive mechanism which stimulates members to contribute content as much as possible. Although the downloading performance in PTs with high Seeder-to-Leecher Ratio (SLR) is much better than in public BitTorrent communities, our measurements show that SRE mechanism can induce 'Poor Downloading Motivation' problem for members who want to increase their sharing ratios to survive and thrive in PT. This problem may discourage PT members' enthusiasm from contributing to community. To improve sustainability of PTs, we adopt the Predator-prey model to analyze high SLR phenomenon, study the optimal stable SLR range to PTs. Moreover, we develop a queuing model to simulate the seeding/leeching process in a single torrent in PT, and try to maximize the swarming performance with minimum seeding peers. This solution can help PT achieve the optimal SLR range. [ABSTRACT FROM AUTHOR]

We consider the problem of sharing a viral file between users in a local community network (e.g., college and office campuses). Community computing is computer networking among and between users in a geographically bounded setting for local purposes and activities. Due to the community-oriented nature of such networks, it is likely that users of a community network would like to share content. Peer-to-Peer (P2P) networks have turned out to be one of the most innovative paradigms for sharing content on the Internet. In this paper, we analyze the performance of P2P content sharing in community networks and investigate the role that infrastructure nodes ( helpers) can play to enhance the performance of content sharing and distribution. We model the evolution of content demand in a community network. The use of this demand prediction model allows us to design a delicate P2P-with-helpers content distribution system. Our insights that we obtain using fluid-flow model increase our understanding of how helper provisioning affects the performance of content sharing and distribution. The derived results show that significant reduction in both the cost of distributing content and the average content download time can be realized when only few infrastructure nodes in the community network play the role helpers and cache P2P objects. [ABSTRACT FROM AUTHOR]

The fast-growing traffic of peer-to-peer (P2P) applications, most notably BitTorrent, is putting unprecedented pressure to Internet Service Providers (ISPs). To address this challenge, a number of P2P traffic management schemes have been proposed in recent years, among which caching and redirection are two representatives. Both of them have shown their success in theory and in practice. Yet, their implementations are largely independent, making the overall effectiveness sub-optimal. In this paper, we for the first time examine the joint implementation of these two promising solutions under a coherent framework, Tod-Cache (Traffic Orientated Distributed Caching). We show that the combination of caching and redirection can dramatically reduce the P2P traffic traversing across ISPs. Under this framework, we formulate the optimal caching and redirection problem, and show its complexity. We then present a highly adaptive and scalable heuristic algorithm which achieves close-to-optimal performance with much lower computational complexity. We extensively evaluate our framework under diverse network and end-system configurations. Our simulation results show that, under the same configuration, it can achieve at least 85 % of performance of the traditional cache with at most 1/10 of the device number. [ABSTRACT FROM AUTHOR]

In past few years, distributed hash table (DHT)-based P2P systems have been proven to be a promising way to manage decentralized index information and provide efficient lookup services. However, the skewness of users' preferences regarding keywords contained in a multi-keyword query causes a query load imbalance that combines both routing and response load. This imbalance means long file retrieval latency that negatively influences the overall system performance. Although index replication has a great potential for alleviating this problem, existing schemes did not explicitly address it or incurred high cost. To overcome this issue, we propose, in this paper, an integrated solution that consists of three replication schemes to alleviate query load imbalance while minimizing the cost. The first scheme is an active index replication that is used in order to decrease routing load in the system and to distribute response load of an index among peers that store replicas of the index. The second scheme is a proactive pointer replication that places location information of each index to a predetermined number of peers for reducing maintenance cost between the index and its replicas. The third scheme is a passive index replication that guarantees the maximum query load of peers. The result of simulations indicates that the proposed schemes can help alleviate the query load imbalance of peers. Moreover, it was found by comparison that our schemes are more cost-effective on placing replicas than PCache and EAD. [ABSTRACT FROM AUTHOR]

The article offers information on the history, purpose and significance of the early discovery in copyright infringement lawsuits against users of the peer-to-peer (P2P) file sharing protocol BitTorrent such as John Doe under the U.S. Federal Rule of Civil Procedure. It discusses legal issue arising from joinder of multiple defendants and motions to quash subpoenas are considered under the copyright law of the U.S.

The anonymizing peer to peer (P2P) system is frequently incurred additional expense in order to efficiency transfer and various systems execute to disguise the uniqueness privacy considerations issues for their users. Although, an anonymity technique mostly existing path base peer before transmits, it has pre-create an anonymous path. An information as well as maintenance transparency of path is a lot high. In this paper it has been proposed mutual anonymity rumor riding (RR) protocol for decentralization environment P2P systems. The very heavy load path construction carries by RR system using random walk mechanism for free initiate peers. We evaluate with before RSA based and also anonymity approach based on AES, RR get extra benefit of lower cryptographic overhead mostly to get anonymity using asymmetric cryptographic algorithm. We illustrate design and effectiveness during the simulations by trace driven. RR is very effect and efficient than previous protocols the experimental and analytical result shows us. [ABSTRACT FROM AUTHOR]