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Peer-to-Peer Computing, 2004. Proceedings. Proceedings. Fourth International Conference on

Date 25-27 Aug. 2004

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Displaying Results 1 - 25 of 52
  • P2P-based collaborative spam detection and filtering

    Page(s): 176 - 183
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    Spam is one of the major problems of today email systems. While many solutions have been proposed to automatically detect and filter spam, spammers are getting more and more technically sophisticated and aware of internal workings of anti-spam systems, finding ways to disguise their emails to get around the different controls that can be enforced. We propose a decentralized privacy-preserving approach to spam filtering. Our solution exploits robust digests to identify messages that are a slight variation of one another and a structured peer-to-peer architecture between mail servers to collaboratively share knowledge about spam. View full abstract»

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  • On de Bruijn routing in distributed hash tables: there and back again

    Page(s): 159 - 166
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (314 KB) |  | HTML iconHTML  

    We show in this paper that de Bruijn networks, despite providing efficient search while using constant routing table size, as well as simplicity of the understanding and implementation of such networks, are unsuitable where key distribution will be uneven, a realistic scenario for most practical applications. In presence of arbitrarily skewed data distribution, it has only recently been shown that some traditional P2P overlay networks with non-constant (typically logarithmic) instead of constant routing table size can meet conflicting objectives of storage load balancing as well as search efficiency. So this paper, while showing that de Bruijn networks fail to meet these dual objectives, opens up a more general problem for the research community as to whether P2P systems with constant routing table can at all achieve the conflicting objectives of retaining search efficiency as well as storage load balancing, while preserving key ordering (which leads to uneven key distribution). View full abstract»

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  • Semantic driven hashing (SDH): an ontology-based search scheme for the semantic aware network (SA Net)

    Page(s): 270 - 271
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (230 KB) |  | HTML iconHTML  

    The success of personalized resource discovery depends on its ability to allow users to discover, extract and integrate information of interest from heterogeneous sources, and its ability to provide these users with efficient tools to manipulate and convert the discovered information into knowledge. We propose semantic aware network (SA Net), a structured peer-to-peer (P2P) overlay architecture to support the basic functionalities of a personalized resource discovery. The SA Net uses an ontology-based representation of the resources to enable a semantic resource discovery and access that reflects the interest of the user. We describe the SA Net search scheme "semantic-driven hashing " (SDH), which uses lexical-based ontology to provide a foundation for indexing and search in structured P2P overlay infrastructure. View full abstract»

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  • A framework for developing reflective and dynamic P2P networks (RaDP2P)

    Page(s): 282 - 283
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (219 KB) |  | HTML iconHTML  

    There has been a significant body of research conducted into various structured and unstructured overlay network protocols. Both paradigms have advantages for specific application domains and researchers are beginning to examine the benefits of using hybridized systems. We hypothesize that resource awareness and adaptation are essential to the efficient exploitation of the resources available on the diverse nodes which compose peer-to-peer networks. To support this, we propose a hybrid peer-to-peer model which uses an unstructured decentralised network layered on top of a structured overlay to provide support for multiple levels of adaptation. View full abstract»

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  • Percolation search in power law networks: making unstructured peer-to-peer networks scalable

    Page(s): 2 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (321 KB) |  | HTML iconHTML  

    We introduce a scalable searching protocol for locating and retrieving content in random networks with power-law (PL) and heavy-tailed degree distributions. The proposed algorithm is capable of finding any content in the network with probability one in time O(logN), with a total traffic that provably scales sub-linearly with the network size, N. Unlike other proposed solutions, there is no need to assume that the network has multiple copies of contents; the protocol finds all contents reliably, even if every node in the network starts with a unique content. The scaling behavior of the size of the giant connected component of a random graph with heavy tailed degree distributions under bond percolation is at the heart of our results. The percolation search algorithm can be directly applied to make unstructured peer-to-peer (P2P) networks, such as Gnutella, Limewire and other file-sharing systems (which naturally display heavy-tailed degree distributions and scale-free network structures), scalable. For example, simulations of the protocol on the limewire crawl number 5 network, consisting of over 65,000 links and 10,000 nodes, shows that even for this snapshot network, the traffic can be reduced by a factor of at least 100, and yet achieve a hit-rate greater than 90%. View full abstract»

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  • On the security of polling protocols in peer-to-peer systems

    Page(s): 36 - 44
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (281 KB) |  | HTML iconHTML  

    The peer-to-peer (P2P) network model differs from the well established client-server model in that all members of the network are assigned an equal role. P2P networks are recently gaining increasing popularity. Providing security in distributed content sharing in P2P networks is an important challenge. This paper identifies security vulnerabilities in the protocols for sharing servants' reputations in the Gnutella P2P system, proposed recently. It demonstrates attacks on the protocols that allow an attacker to alter the results of the voting procedure. The paper then presents a protocol that is resilient to the attacks described. In the proposed protocol, enhanced security against various attacks is achieved using smart design and a combination of various techniques such as the use of digital signatures for message integrity and random numbers for message freshness. View full abstract»

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  • Broose: a practical distributed hashtable based on the de-Bruijn topology

    Page(s): 167 - 174
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    Broose is a peer-to-peer protocol based on the de Bruijn topology allowing a distributed hashtable to be maintained in a loose manner. Each association is stored on k nodes to allow higher reliability with regard to node failures. Redundancy is also used when storing contacts avoiding complex topology maintenance for node departures and arrivals. It uses a constant size routing table of 0(k) contacts for allowing lookups in O(log N) message exchange (where N is the number of nodes participating). It can also be parameterized for obtaining O(log N / log log N) steps lookups with a routing table of size 0(k log N). These bounds hold with high probability. Moreover, the protocol allows load balancing of hotspots of requests for a given key as well as hotspots of key collisions. The goal is to obtain a protocol as practical as Kademlia based on the de Bruijn topology. View full abstract»

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  • Cooperative pull-push cycle for searching a hybrid P2P network

    Page(s): 192 - 199
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (594 KB) |  | HTML iconHTML  

    Information acquisition is a great challenge in the context of a continually growing Web. Nowadays, large Web search engines are primarily designed to assist an information pull by the user. On this platform, only actual information needs are handled without assistance of long-term needs. To overcome these shortcomings we propose a cooperative system for information pull and push on a peer-to-peer architecture. We present a hybrid network for a collaborative search environment, based on a local personalization strategy on each peer, and a highly-available Web search service (e.g. Google). Each peer participates in the pull-push cycle, and has the function of an information consumer as well as an information provider. Hence, long-term information needs can be identified without any context restrictions, and recommendations are computed based on virtual knowledge communities. View full abstract»

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  • P2P applications using the semantic information oriented network

    Page(s): 272 - 273
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (602 KB) |  | HTML iconHTML  

    This paper describes P2P applications using an advanced P2P platform called SIONet. Based on its metadata-based routing and easy communication creation capabilities, various kinds of P2P applications can be constructed. Effective discovery, P2P content delivery with digital rights management, semi-active information exchanging community, and P2P ad hoc community are constructed. These are expected to be bases for next generation ubiquitous applications. View full abstract»

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  • ICN: interest-based clustering network

    Page(s): 219 - 226
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB) |  | HTML iconHTML  

    An interest-based clustering peer-to-peer network (ICN) architecture is introduced in this paper. ICN uses a lot of Freenet mechanisms and is based on cache management. ICN is self-organizing, fully distributed, scalable, and logically hierarchical. In ICN, the upper level is bound by de Bruijn graph. Nodes in the lower level self-cluster based on interest. Through analysis and simulation, ICN shows good fault-tolerance, efficient data retrieval and resource usage as well as low overhead traffic. View full abstract»

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  • SeAl: managing accesses and data in peer-to-peer sharing networks

    Page(s): 116 - 123
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (490 KB) |  | HTML iconHTML  

    We present SeAl, a novel data/resource and data-access management infrastructure designed for the purpose of addressing a key problem in P2P data sharing networks, namely the problem of wide-scale selfish peer behavior. Selfish behavior has been manifested and well documented and it is widely accepted that unless this is dealt with, the scalability, efficiency, and the usefulness of P2P sharing networks will be diminished. SeAl essentially consists of a monitoring/accounting subsystem, an auditing/verification subsystem, and incentive mechanisms. The monitoring subsystem facilitates the classification of peers into selfish/altruistic. The auditing/verification layer provides a shield against perjurer/slandering and colluding peers that may try to cheat the monitoring subsystem. The incentives mechanisms effectively utilize these layers so to increase the computational/networking and data resources that are available to the community. Our extensive performance results show that SeAl performs its tasks swiftly, while the overhead introduced by our accounting and auditing mechanisms in terms of response time, network, and storage overheads are very small. View full abstract»

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  • Cache updates in a peer-to-peer network of mobile agents

    Page(s): 10 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB) |  | HTML iconHTML  

    In open multi-agent systems, agents need resources provided by other agents but they are not aware of which agents provide particular resources. We consider a peer-to-peer approach, in which each agent maintains a local cache with information about k resources, that is for each of the k resources, an agent that provides it. However, when an agent or a resource moves, cache entries become obsolete. We propose a suite of cache update policies that combine pull-based invalidation that is initiated by the agent that maintains the cache with push-based invalidation that is initiated by the agent that moves. We study and compare variations of oblivious flooding-based push/pull along with an informed push approach where each agent maintains a list of the agents that have it cached. Our experimental results indicate that a novel variation of flooding for push where a moving agent propagates its new location to agents in its old neighborhood achieves good cache consistency with a small message overhead. The proposed policies are suitable for any peer-to-peer system where peers cache information about other peers and this information becomes obsolete. View full abstract»

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  • The different dimensions of dynamicity

    Page(s): 244 - 251
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (598 KB) |  | HTML iconHTML  

    In a peer-to-peer (P2P) network, a 'fabric' of overlay links helps peers discover and use other peers' resources. This fabric, however, is highly dynamic and constantly changing. While different measures of dynamicity have been implicitly and explicitly proposed, there is lack of deeper understanding about the various aspects of dynamicity. We systematically evaluate and quantify different dimensions of dynamicity through controlled generation of different dynamic networks. We also introduce a new dimension of dynamicity, persistence, which quantifies stable nodes in a network. This measure could be quite useful in the design and testing of P2P protocols that exploit the presence of stable nodes. Also, quite coincidentally, and to our surprise, a certain type of dynamic network that we designed has node degree properties that resemble those observed in social networks. View full abstract»

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  • Latency model of a distributed hash table with big routing table

    Page(s): 274 - 275
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (215 KB) |  | HTML iconHTML  

    In peer-to-peer research, one of the most popular areas is distributed hash table (DHT). Among many topics in the DHT area, this paper focuses on DHT latencies, which are mainly caused by its basic multi-hop lookup function. Some DHTs already have the capability of building big routing tables to reduce hop counts. However, none of them are explicitly trying to enlarge the routing table and lower the hop count. This paper provides a simple latency model of DHT and discusses how big routing tables help reduce latency. View full abstract»

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  • Reputation management framework and its use as currency in large-scale peer-to-peer networks

    Page(s): 124 - 132
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (417 KB) |  | HTML iconHTML  

    We propose a reputation management framework for large-scale peer-to-peer (P2P) networks, wherein all nodes are assumed to behave selfishly. The proposed framework has several advantages. It enables a form of virtual currency, such that the reputation of nodes is a measure of their wealth. The framework is scalable and provides protection against attacks by malicious nodes. The above features are achieved by developing trusted communities of nodes whose members trust each other and cooperate to deal with the problem of nodes' selfishness and possible maliciousness. View full abstract»

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  • Information leak in the Chord lookup protocol

    Page(s): 28 - 35
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (533 KB) |  | HTML iconHTML  

    In peer-to-peer (P2P) systems, it is often essential that connected systems (nodes) relay messages which did not originate locally, on to the greater network. As a result, an intermediate node might be able to determine a large amount of information about the system, such as the querying tendencies of other nodes. This represents an inherent security issue in P2P networks. Therefore, we ask the following question: through the observation of the network traffic in a P2P network, what kind of information can an adversarial node learn about another node in the same network? We study this question in the case of a specific P2P system - Chord. We also study the effects of the parameters of Chord (such as finger-table size) and the various enhancements to Chord (such as location caching and data caching) on the amount of information leaked. View full abstract»

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  • Semantic-laden peer-to-peer service directory

    Page(s): 184 - 191
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    The most intuitive way to build a service directory application that allows for service entities to register or search for services on top of a structured peer-to-peer network is to build reverse indices at appropriate nodes on the network. However, this implies trust on the reliability and integrity of other nodes on the network, which may be too risky an assumption for businesses. This paper proposes a service directory that groups service entities of the same category together; this is achieved by dedicating part of the node identifiers to correspond to their service category semantic. Using chord as the peer-to-peer substrate, this scheme logically divides the chord circle into equidistant arcs; each arc is called an island. This scheme results in the formation of islands of varying population, and thus changing the uniformly spread topology of the original chord. Simulations are used to investigate the path length and message load of the changed topology. An additional routing scheme is also proposed and simulated to exploit the new topology to gain better path length. View full abstract»

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  • P2P-4-DL: digital library over peer-to-peer

    Page(s): 264 - 265
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    The P2P-4-DL project aims to investigate and build a DL system that would operate over a P2P structure. Rather than storing digital objects centrally they remain the responsibility of the individual peers that provide them. This allows the system to utilise network resources more efficiently as well as providing users with a greater sense of control over the digital objects they share. Our prototype also draws upon natural language processing (NLP) techniques in an attempt to increase the usability of the system. Other related work within this area includes EDUTELLA, a RDF based P2P infrastructure that can support the development of DL's. View full abstract»

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  • Adaptive peer-to-peer topologies

    Page(s): 53 - 62
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (334 KB) |  | HTML iconHTML  

    We present a peer-level protocol for forming adaptive, self-organizing topologies for data-sharing P2P networks. This protocol is based on the idea that a peer should directly connect to those peers from which it is most likely to download satisfactory content. We show that the resulting topologies are more efficient than standard Gnutella topologies. Furthermore, we show that these adaptive topologies have the added benefits of increased resistance to certain types of attacks, intrinsic rewards for active peers and punishments for malicious peers and free riders. View full abstract»

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  • Performance of Pastry in a heterogeneous system

    Page(s): 278 - 279
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (289 KB) |  | HTML iconHTML  

    We study how Pastry performs in a heterogeneous network environment of varying size. The large traffic overhead for management traffic makes the overlay nonfunctional if it grows too large. This can be circumvented by partitioning the routing tables at the cost of increased path lengths and response times. View full abstract»

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  • Aggregating information in peer-to-peer systems for improved join and leave

    Page(s): 227 - 234
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (321 KB) |  | HTML iconHTML  

    We introduce the Distributed Approximative System Information Service (DASIS) as a useful scheme to aggregate approximative information on the state of a peer-to-peer system. We present how this service can be integrated into existing peer-to-peer systems, such as Kademlia and Chord. As a sample application, we show how DASIS can be employed for establishing an effective deterministic join algorithm. Through simulation, we demonstrate that the insertion of peers using DASIS information results in a well-balanced system. Moreover, our join algorithm gracefully resolves load imbalances in the system due to unfortunate biased leaves of peers. View full abstract»

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  • Erasure code replication revisited

    Page(s): 90 - 97
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (396 KB) |  | HTML iconHTML  

    Erasure coding is a technique for achieving high availability and reliability in storage and communication systems. We revisit the analysis of erasure code replication and point out some situations when whole-file replication is preferred. The switchover point (from preferring whole-file replication to erasure code replication) is studied, and characterized using asymptotic analysis. We also discuss the additional considerations in building erasure code replication systems. View full abstract»

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  • Analysis and application of passive peer influence on peer-to-peer inter-domain traffic

    Page(s): 142 - 150
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4843 KB) |  | HTML iconHTML  

    As a result of widespread of peer-to-peer (P2P) file sharing applications, it is a serious problem that inter-domain traffic between Internet service provider (ISP) networks increases. We present a novel inter-domain traffic flow model focusing on the presence of a passive peer, and proposes a new P2P traffic control method based on the model. This method uses a filter considering P2P flow characteristics and can be applied to the P2P networks whose protocol is closed. We also evaluate both validity and effectiveness of our proposals by performing more than 20 days experiments using real P2P network environment. The results prove that our model is reasonable enough and the proposed method is promising for decreasing inter-domain P2P traffic. View full abstract»

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  • PROST: a programmable structured peer-to-peer overlay network

    Page(s): 280 - 281
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (220 KB) |  | HTML iconHTML  

    We present the idea of a programmable structured P2P architecture. Our proposed system allows the key-based routing infrastructure, which is common to all structured P2P overlays, to be shared by multiple applications. Furthermore, our architecture allows the dynamic and on-demand deployment of new applications and services on top of the shared routing layer. View full abstract»

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  • A robust protocol for building superpeer overlay topologies

    Page(s): 202 - 209
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (495 KB) |  | HTML iconHTML  

    The concept of superpeer has been introduced to improve the performance of popular file-sharing applications. A superpeer is a node in a P2P network that operates as a server for a set of clients, and as an equal w.r.t. other superpeers. By exploiting heterogeneity, the superpeer paradigm allows P2P networks to run more efficiently, without compromising their decentralized nature. This paper describes SG-1, a novel generic mechanism for the construction and the maintenance of overlay topologies based on superpeers. SG-1 is based on the well-known gossip paradigm, with nodes exchanging information with randomly selected peers and re-arranging the topology according to the requirements of the particular P2P application. The resulting protocol is extremely efficient and robust, capable to deal with a continuous flow of nodes joining and leaving the system, as well as to repair a network where up to 100% of the existing super-peers have been removed. View full abstract»

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