Small-World File-Sharing Communities

Web caches, content distribution networks, peer-to-peer file sharing networks, distributed file systems, and data grids all have in common that they involve a community of users who generate requests for shared data. In each case, overall system performance can be improved significantly if we can first identify and then exploit interesting structure within a community's access patterns. To this end, we propose a novel perspective on file sharing based on the study of the relationships that form among users based on the files in which they are interested. We propose a new structure that captures common user interests in data--the data-sharing graph-- and justify its utility with studies on three data-distribution systems: a high-energy physics collaboration, the Web, and the Kazaa peer-to-peer network. We find small-world patterns in the data-sharing graphs of all three communities. We analyze these graphs and propose some probable causes for these emergent small-world patterns. The significance of small-world patterns is twofold: it provides a rigorous support to intuition and, perhaps most importantly, it suggests ways to design mechanisms that exploit these naturally emerging patterns

Evidence Collection for Forensic Investigation in Peer to Peer Systems

Abstract Peer to Peer(P2P) file sharing networks are amongst the best free sources of information on the internet. Voluntary participation and lack of control makes them a very attractive option to share data anonymously. However a small group of people take advantage of the freedom provided by these networks and share content that is prohibited by law. Apart from copyrighted content, there are cases where people share les related to Child Pornography which is a criminal offense. Law enforcement attempts to track down these offenders by obtaining a court order for search and seizure of computers at a suspect location. These seized computers are forensically examined using storage and memory-forensics tools. However before the search warrant is issued strong evidence must be presented to provide a reason for suspiscion. Deficient investigation in the intial stages might lead to mis-identification of the source and steer the investigation in a wrong direction. Initial evidence collection on peer to peer le sharing networks is a challenge due to the lack of a central point of control and highly dynamic nature of the networks. The goal of this work is to create a working prototype of an initial evidence collection tool for forensics in P2P networks. The prototype is based on the idea that P2P networks could be monitored by introducing modified peer nodes onto the network for a certain time period and recording relevant information about nodes that possess criminally offensive content. Logging information sent by a suspicious node along with timestamps and unique identication information would provide a strong, verfiiable initial evidence. This work presents one such working prototype in alignment with the goals stated above

Self-organizing peer-to-peer social networks

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 The Authors.Peer-to-peer (P2P) systems provide a new solution to distributed information and resource sharing because of its outstanding properties in decentralization, dynamics, flexibility, autonomy, and cooperation, summarized as DDFAC in this paper. After a detailed analysis of the current P2P literature, this paper suggests to better exploit peer social relationships and peer autonomy to achieve efficient P2P structure design. Accordingly, this paper proposes Self-organizing peer-to-peer social networks (SoPPSoNs) to self-organize distributed peers in a decentralized way, in which neuron-like agents following extended Hebbian rules found in the brain activity represent peers to discover useful peer connections. The self-organized networks capture social associations of peers in resource sharing, and hence are called P2P social networks. SoPPSoNs have improved search speed and success rate as peer social networks are correctly formed. This has been verified through tests on real data collected from the Gnutella system. Analysis on the Gnutella data has verified that social associations of peers in reality are directed, asymmetric and weighted, validating the design of SoPPSoN. The tests presented in this paper have also evaluated the scalability of SoPPSoN, its performance under varied initial network connectivity and the effects of different learning rules.National Natural Science of Foundation of Chin

Fault-tolerant routing in peer-to-peer systems

We consider the problem of designing an overlay network and routing mechanism that permits finding resources efficiently in a peer-to-peer system. We argue that many existing approaches to this problem can be modeled as the construction of a random graph embedded in a metric space whose points represent resource identifiers, where the probability of a connection between two nodes depends only on the distance between them in the metric space. We study the performance of a peer-to-peer system where nodes are embedded at grid points in a simple metric space: a one-dimensional real line. We prove upper and lower bounds on the message complexity of locating particular resources in such a system, under a variety of assumptions about failures of either nodes or the connections between them. Our lower bounds in particular show that the use of inverse power-law distributions in routing, as suggested by Kleinberg (1999), is close to optimal. We also give efficient heuristics to dynamically maintain such a system as new nodes arrive and old nodes depart. Finally, we give experimental results that suggest promising directions for future work.Comment: Full version of PODC 2002 paper. New version corrects missing conditioning in Lemma 9 and some related details in the proof of Theorem 10, with no changes to main result

Open Peer to Peer Technologies

Peer-to-peer applications allow us to separate out the concepts of authoring information and publishing that same information. It allows for decentralized application design, something that is both an opportunity and a challenge. All the peer-to-peer applications, in various ways, return the content, choice, and control to ordinary users. Tiny end points on the Internet, sometimes even without knowing each other, exchange information and form communities. In these applications there are no more clients and servers, instead the communication takes place between cooperating peers. There are many applications nowadays which are being labeled as peer-to-peer. A way to examine the distinction of whether an application is peer-to-peer or not is to check on the owner of the hardware that the service runs on. Like Napster, if the huge part of the hardware that Napster runs on is owned by the Napster users on millions of desktops then it is peer-to-peer. Peer-to-peer is a way of decentralizing not only features, but costs and administration also. By decentralizing data and therefore redirecting users so they download data directly from other user's computers, Napster reduced the load on its servers to the point where it could cheaply support tens of millions of users. The same principle is used in many commercial peer-to-peer systems. In short peer-to-peer cannot only distribute files. It can also distribute the burden of supporting network connections. The overall bandwidth remains the same as in centralized systems, but bottlenecks are eliminated at central sites and equally importantly, at their ISPs. Search techniques are important to making peer-to-peer systems useful. But there is a higher level of system design and system use. Topics like trust, accountability and metadata have to be handled before searching is viable

Peer to Peer Information Retrieval: An Overview

Peer-to-peer technology is widely used for file sharing. In the past decade a number of prototype peer-to-peer information retrieval systems have been developed. Unfortunately, none of these have seen widespread real- world adoption and thus, in contrast with file sharing, information retrieval is still dominated by centralised solutions. In this paper we provide an overview of the key challenges for peer-to-peer information retrieval and the work done so far. We want to stimulate and inspire further research to overcome these challenges. This will open the door to the development and large-scale deployment of real-world peer-to-peer information retrieval systems that rival existing centralised client-server solutions in terms of scalability, performance, user satisfaction and freedom

Integrating Peer-to-Peer Networking and Computing in the AgentScape Framework

The combination of peer-to-peer networking and agentbased computing seems to be a perfect match. Agents are cooperative and communication oriented, while peerto -peer networks typically support distributed systems in which all nodes have equal roles and responsibilities. AgentScape is a framework designed to support large-scale multi-agent systems. Pole extends this framework with peerto -peer computing. This combination facilitates the development and deployment of new agent-based peer-to-peer applications and services

Adaptive service discovery on service-oriented and spontaneous sensor systems

Service-oriented architecture, Spontaneous networks, Self-organisation, Self-configuration, Sensor systems, Social patternsNatural and man-made disasters can significantly impact both people and environments. Enhanced effect can be achieved through dynamic networking of people, systems and procedures and seamless integration of them to fulfil mission objectives with service-oriented sensor systems. However, the benefits of integration of services will not be realised unless we have a dependable method to discover all required services in dynamic environments. In this paper, we propose an Adaptive and Efficient Peer-to-peer Search (AEPS) approach for dependable service integration on service-oriented architecture based on a number of social behaviour patterns. In the AEPS network, the networked nodes can autonomously support and co-operate with each other in a peer-to-peer (P2P) manner to quickly discover and self-configure any services available on the disaster area and deliver a real-time capability by self-organising themselves in spontaneous groups to provide higher flexibility and adaptability for disaster monitoring and relief

Structured P2P Technologies for Distributed Command and Control

The utility of Peer-to-Peer (P2P) systems extends far beyond traditional file sharing. This paper provides an overview of how P2P systems are capable of providing robust command and control for Distributed Multi-Agent Systems (DMASs). Specifically, this article presents the evolution of P2P architectures to date by discussing supporting technologies and applicability of each generation of P2P systems. It provides a detailed survey of fundamental design approaches found in modern large-scale P2P systems highlighting design considerations for building and deploying scalable P2P applications. The survey includes unstructured P2P systems, content retrieval systems, communications structured P2P systems, flat structured P2P systems and finally Hierarchical Peer-to-Peer (HP2P) overlays. It concludes with a presentation of design tradeoffs and opportunities for future research into P2P overlay systems