A survey of peer-to-peer content distribution technologies
---
paper_title: Scan: A dynamic, scalable, and efficient content distribution network

paper_content:

We present SCAN, the Scalable Content Access Network. SCAN combines dynamic replica placement with a self-organizing application-level multicast tree to meet client QoS and server resource constraints. It utilizes an underlying distributed object routing and location system (DOLR) as an essential component.Sim ulation results on both flash-crowd-like synthetic workloads and realWeb server traces show that SCAN deploys close to an optimal number of replicas, achieves good load balance, and incurs a small delay and bandwidth penalty for update multicast relative to static replica placement on IP multicast. We envision that SCAN could enhance a number of different applications, such as content distribution and peer-to-peer file sharing.
---
paper_title: Peer-to-peer prospects

paper_content:

The P2P design philosophy needs far more detail before we can appreciate a clear picture of its potential.
---
paper_title: P2P and the promise of internet equality

paper_content:

Technologies often come wrapped in stories about politics. These stories may not explain the motives of the technologists, but they do often explain the social energy that propels the technology into the larger world. In the case of P2P technologies, the official engineering story is that computational effort should be distributed to reflect the structure of the problem. But the engineering story does not explain the strong feelings P2P computing often evokes. The strong feelings derive from a political story, often heatedly disavowed by technologists but widespread in the culture: P2P delivers on the Internet's promise of decentralization. By minimizing the role of centralized computing elements, the story goes, P2P systems will be immune to censorship, monopoly, regulation, and other exercises of centralized authority.
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paper_title: Internet indirection infrastructure

paper_content:

Attempts to generalize the Internet's point-to-point communication abstraction to provide services like multicast, anycast, and mobility have faced challenging technical problems and deployment barriers. To ease the deployment of such services, this paper proposes a general, overlay-based Internet Indirection Infrastructure (i3) that offers a rendezvous-based communication abstraction. Instead of explicitly sending a packet to a destination, each packet is associated with an identifier; this identifier is then used by the receiver to obtain delivery of the packet. This level of indirection decouples the act of sending from the act of receiving, and allows i3 to efficiently support a wide variety of fundamental communication services. To demonstrate the feasibility of this approach, we have designed and built a prototype based on the Chord lookup protocol.
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paper_title: On Death, Taxes, and the Convergence of Peer-to-Peer and Grid Computing

paper_content:

It has been reported [25] that life holds but two certainties, death and taxes. And indeed, it does appear that any society-and in the context of this article, any large-scale distributed system-must address both death (failure) and the establishment and maintenance of infrastructure (which we assert is a major motivation for taxes, so as to justify our title!).
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paper_title: Data Management for Peer-to-Peer Computing : A Vision

paper_content:

We motivate special database problems introduced by peer-to-peer computing and propose the Local Relational Model (LRM) to solve some of them. As well, we summarize a formalization of LRM, present an architecture for a prototype implementation, and discuss open research questions.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: OceanStore: an architecture for global-scale persistent storage

paper_content:

OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development.
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paper_title: Piazza: data management infrastructure for semantic web applications

paper_content:

The Semantic Web envisions a World Wide Web in which data is described with rich semantics and applications can pose complex queries. To this point, researchers have defined new languages for specifying meanings for concepts and developed techniques for reasoning about them, using RDF as the data model. To flourish, the Semantic Web needs to be able to accommodate the huge amounts of existing data and the applications operating on them. To achieve this, we are faced with two problems. First, most of the world's data is available not in RDF but in XML; XML and the applications consuming it rely not only on the domain structure of the data, but also on its document structure. Hence, to provide interoperability between such sources, we must map between both their domain structures and their document structures. Second, data management practitioners often prefer to exchange data through local point-to-point data translations, rather than mapping to common mediated schemas or ontologies.This paper describes the Piazza system, which addresses these challenges. Piazza offers a language for mediating between data sources on the Semantic Web, which maps both the domain structure and document structure. Piazza also enables interoperation of XML data with RDF data that is accompanied by rich OWL ontologies. Mappings in Piazza are provided at a local scale between small sets of nodes, and our query answering algorithm is able to chain sets mappings together to obtain relevant data from across the Piazza network. We also describe an implemented scenario in Piazza and the lessons we learned from it.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
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paper_title: Querying the Internet with PIER

paper_content:

The database research community prides itself on scalable technologies. Yet database systems traditionally do not excel on one important scalability dimension: the degree of distribution. This limitation has hampered the impact of database technologies on massively distributed systems like the Internet. ::: ::: In this paper, we present the initial design of PIER, a massively distributed query engine based on overlay networks, which is intended to bring database query processing facilities to new, widely distributed environments. We motivate the need for massively distributed queries, and argue for a relaxation of certain traditional database research goals in the pursuit of scalability and widespread adoption. We present simulation results showing PIER gracefully running relational queries across thousands of machines, and show results from the same software base in actual deployment on a large experimental cluster.
---
paper_title: A scalable content-addressable network

paper_content:

Hash tables - which map "keys" onto "values" - are an essential building block in modern software systems. We believe a similar functionality would be equally valuable to large distributed systems. In this paper, we introduce the concept of a Content-Addressable Network (CAN) as a distributed infrastructure that provides hash table-like functionality on Internet-like scales. The CAN is scalable, fault-tolerant and completely self-organizing, and we demonstrate its scalability, robustness and low-latency properties through simulation.
---
paper_title: Kademlia: A Peer-to-Peer Information System Based on the XOR Metric

paper_content:

We describe a peer-to-peer distributed hash table with provable consistency and performance in a fault-prone environment. Our system routes queries and locates nodes using a novel XOR-based metric topology that simplifies the algorithm and facilitates our proof. The topology has the property that every message exchanged conveys or reinforces useful contact information. The system exploits this information to send parallel, asynchronous query messages that tolerate node failures without imposing timeout delays on users.
---
paper_title: Tapestry : An Infrastructure for Fault-tolerant Wide-area Location and Routing

paper_content:

In today''s chaotic network, data and services are mobile and replicated widely for availability, durability, and locality. Components within this infrastructure interact in rich and complex ways, greatly stressing traditional approaches to name service and routing. This paper explores an alternative to traditional approaches called Tapestry. Tapestry is an overlay location and routing infrastructure that provides location-independent routing of messages directly to the closest copy of an object or service using only point-to-point links and without centralized resources. The routing and directory information within this infrastructure is purely soft state and easily repaired. Tapestry is self-administering, fault-tolerant, and resilient under load. This paper presents the architecture and algorithms of Tapestry and explores their advantages through a number of experiments.
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paper_title: Onion Routing for Anonymous and Private Internet Connections

paper_content:

Abstract : Preserving privacy means not only hiding the content of messages, but also hiding who is talking to whom (traffic analysis). Much like a physical envelope, the simple application of cryptography within a packet-switched network hides the messages being sent, but can reveal who is talking to whom, and how often. Onion Routing is a general purpose infrastructure for private communication over a public network [8, 9, 4]. It provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. The connections are bidirectional, near real-time, and can be used for both connection-based and connectionless traffic. Onion Routing interfaces with off the shelf software and systems through specialized proxies, making it easy to integrate into existing systems. Prototypes have been running since July 1997. As of this article's publication, the prototype network is processing more than 1 million Web connections per month from more than six thousand IP addresses in twenty countries and in all six main top level domains. [7]
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paper_title: Introducing Tarzan, a Peer-to-Peer Anonymizing Network Layer

paper_content:

We introduce Tarzan, a peer-to-peer anonymous network layer that provides generic IP forwarding. Unlike prior anonymizing layers, Tarzan is flexible, transparent, decentralized, and highly scalable.Tarzan achieves these properties by building anonymous IP tunnels between an open-ended set of peers. Tarzan can provide anonymity to existing applications, such as web browsing and file sharing, without change to those applications. Performance tests show that Tarzan imposes minimal overhead over a corresponding non-anonymous overlay route.
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paper_title: Formulations and Formalisms in Software Architecture

paper_content:

Software architecture is the level of software design that addresses the overall structure and properties of software systems. It provides a focus for certain aspects of design and development that are not appropriately addressed within the constituent modules. Architectural design depends heavily on accurate specifications of subsystems and their interactions. These specifications must cover a wide variety of properties, so the specification notations and associated methods must be selected or developed to match the properties of interest. Unfortunately, the available formal methods are only a partial match for architectural needs, which entail description of structure, packaging, environmental assumptions, representation, and performance as well as functionality. A prerequisite for devising or selecting a formal method is sound understanding of what needs to be formalized. For software architecture, much of this understanding is arising through progressive codification, which begins with real-world examples and creates progressively more precise models that eventually support formalization. This paper explores the progressive codification of software architecture: the relation between emerging models and the selection, development, and use of formal systems.
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paper_title: A reputation system for peer-to-peer networks

paper_content:

We investigate the design of a reputation system for decentralized unstructured P2P networks like Gnutella. Having reliable reputation information about peers can form the basis of an incentive system and can guide peers in their decision making (e.g., who to download a file from). The reputation system uses objective criteria to track each peer's contribution in the system and allows peers to store their reputations locally. Reputation are computed using either of the two schemes, debit-credit reputation computation (DCRC) and credit-only reputation computation (CORC). Using a reputation computation agent (RCA), we design a public key based mechanism that periodically updates the peer reputations in a secure, light-weight, and partially distributed manner. We evaluate using simulations the performance tradeoffs inherent in the design of our system.
---
paper_title: A scalable content-addressable network

paper_content:

Hash tables - which map "keys" onto "values" - are an essential building block in modern software systems. We believe a similar functionality would be equally valuable to large distributed systems. In this paper, we introduce the concept of a Content-Addressable Network (CAN) as a distributed infrastructure that provides hash table-like functionality on Internet-like scales. The CAN is scalable, fault-tolerant and completely self-organizing, and we demonstrate its scalability, robustness and low-latency properties through simulation.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: Tapestry : An Infrastructure for Fault-tolerant Wide-area Location and Routing

paper_content:

In today''s chaotic network, data and services are mobile and replicated widely for availability, durability, and locality. Components within this infrastructure interact in rich and complex ways, greatly stressing traditional approaches to name service and routing. This paper explores an alternative to traditional approaches called Tapestry. Tapestry is an overlay location and routing infrastructure that provides location-independent routing of messages directly to the closest copy of an object or service using only point-to-point links and without centralized resources. The routing and directory information within this infrastructure is purely soft state and easily repaired. Tapestry is self-administering, fault-tolerant, and resilient under load. This paper presents the architecture and algorithms of Tapestry and explores their advantages through a number of experiments.
---
paper_title: Managing Gigabytes: Compressing and Indexing Documents and Images

paper_content:

PREFACE 1. OVERVIEW 2. TEXT COMPRESSION 3. INDEXING 4. QUERYING 5. INDEX CONSTRUCTION 6. IMAGE COMPRESSION 7. TEXTUAL IMAGES 8. MIXED TEXT AND IMAGES 9. IMPLEMENTATION 10. THE INFORMATION EXPLOSION A. GUIDE TO THE MG SYSTEM B. GUIDE TO THE NZDL REFERENCES INDEX
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paper_title: Protecting free expression online with Freenet

paper_content:

Freenet is a distributed information storage system designed to address information privacy and survivability concerns. Freenet operates as a self-organizing P2P network that pools unused disk space across potentially hundreds of thousands of desktop computers to create a collaborative virtual file system. Freenet employs a completely decentralized architecture. Given that the P2P environment is inherently untrustworthy and unreliable, we must assume that participants could operate maliciously or fail without warning at any time. Therefore, Freenet implements strategies to protect data integrity and prevent privacy leaks in the former instance, and provide for graceful degradation and redundant data availability in the latter. The system is also designed to adapt to usage patterns, automatically replicating and deleting files to make the most effective use of available storage in response to demand.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: Comparing Hybrid Peer-to-Peer Systems

paper_content:

“Peer-to-peer” systems like Napster and Gnutella have recently become popular for sharing information. In this paper, we study the relevant issues and tradeoffs in designing a scalable P2P system. We focus on a subset of P2P systems, known as “hybrid” P2P, where some functionality is still centralized. (In Napster, for example, indexing is centralized, and file exchange is distributed.) We model a file-sharing application, developing a probabilistic model to describe query behavior and expected query result sizes. We also develop an analytic model to describe system performance. Using experimental data collected from a running, publicly available hybrid P2P system, we validate both models. We then present several hybrid P2P system architectures and evaluate them using our model. We discuss the tradeoffs between the architectures and highlight the effects of key parameter values on system performance.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: Making gnutella-like P2P systems scalable

paper_content:

Napster pioneered the idea of peer-to-peer file sharing, and supported it with a centralized file search facility. Subsequent P2P systems like Gnutella adopted decentralized search algorithms. However, Gnutella's notoriously poor scaling led some to propose distributed hash table solutions to the wide-area file search problem. Contrary to that trend, we advocate retaining Gnutella's simplicity while proposing new mechanisms that greatly improve its scalability. Building upon prior research [1, 12, 22], we propose several modifications to Gnutella's design that dynamically adapt the overlay topology and the search algorithms in order to accommodate the natural heterogeneity present in most peer-to-peer systems. We test our design through simulations and the results show three to five orders of magnitude improvement in total system capacity. We also report on a prototype implementation and its deployment on a testbed.
---
paper_title: Routing indices for peer-to-peer systems

paper_content:

Finding information in a peer-to-peer system currently requires either a costly and vulnerable central index, or flooding the network with queries. We introduce the concept of routing indices (RIs), which allow nodes to forward queries to neighbors that are more likely to have answers. If a node cannot answer a query, it forwards the query to a subset of its neighbors, based on its local RI, rather than by selecting neighbors at random or by flooding the network by forwarding the query to all neighbors. We present three RI schemes: the compound, the hop-count, and the exponential routing indices. We evaluate their performance via simulations, and find that RIs can improve performance by one or two orders of magnitude vs. a flooding-based system, and by up to 100% vs. a random forwarding system. We also discuss the tradeoffs between the different RI schemes and highlight the effects of key design variables on system performance.
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paper_title: Improving search in peer-to-peer networks

paper_content:

Peer-to-peer systems have emerged as a popular way to share huge volumes of data. The usability of these systems depends on effective techniques to find and retrieve data; however current techniques used in existing P2P systems are often very inefficient. We present three techniques for efficient search in P2P systems. We present the design of these techniques, and then evaluate them using a combination of analysis and experiments over Gnutella, the largest open P2P system in operation. We show that while our techniques maintain the same quality of results as currently used techniques, they use up to 5 times fewer resources. In addition, we designed our techniques to be simple, so that they can be easily incorporated into existing systems for immediate impact.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: Exploring the Design Space of Distributed and Peer-to-Peer Systems: Comparing the Web, TRIAD, and Chord/CFS

paper_content:

Despite the existence of many peer-to-peer systems, some of their design choices and implications are not well understood. This paper compares several distributed and peer-to-peer systems by evaluating a key set of architectural decisions: naming, addressing, routing, topology, and name lookup. Using the World Wide Web, Triad, and Chord/CFS as examples, we illustrate how different architectural choices impact availability, redundancy, security, and fault-tolerance.
---
paper_title: A scalable content-addressable network

paper_content:

Hash tables - which map "keys" onto "values" - are an essential building block in modern software systems. We believe a similar functionality would be equally valuable to large distributed systems. In this paper, we introduce the concept of a Content-Addressable Network (CAN) as a distributed infrastructure that provides hash table-like functionality on Internet-like scales. The CAN is scalable, fault-tolerant and completely self-organizing, and we demonstrate its scalability, robustness and low-latency properties through simulation.
---
paper_title: Kademlia: A Peer-to-Peer Information System Based on the XOR Metric

paper_content:

We describe a peer-to-peer distributed hash table with provable consistency and performance in a fault-prone environment. Our system routes queries and locates nodes using a novel XOR-based metric topology that simplifies the algorithm and facilitates our proof. The topology has the property that every message exchanged conveys or reinforces useful contact information. The system exploits this information to send parallel, asynchronous query messages that tolerate node failures without imposing timeout delays on users.
---
paper_title: Host extensions for IP multicasting

paper_content:

This memo specifies the extensions required of a host implementation ::: of the Internet Protocol (IP) to support multicasting. Recommended ::: procedure for IP multicasting in the Internet. This RFC obsoletes RFCs ::: 998 and 1054. [STANDARDS-TRACK]
---
paper_title: Tapestry : An Infrastructure for Fault-tolerant Wide-area Location and Routing

paper_content:

In today''s chaotic network, data and services are mobile and replicated widely for availability, durability, and locality. Components within this infrastructure interact in rich and complex ways, greatly stressing traditional approaches to name service and routing. This paper explores an alternative to traditional approaches called Tapestry. Tapestry is an overlay location and routing infrastructure that provides location-independent routing of messages directly to the closest copy of an object or service using only point-to-point links and without centralized resources. The routing and directory information within this infrastructure is purely soft state and easily repaired. Tapestry is self-administering, fault-tolerant, and resilient under load. This paper presents the architecture and algorithms of Tapestry and explores their advantages through a number of experiments.
---
paper_title: Scan: A dynamic, scalable, and efficient content distribution network

paper_content:

We present SCAN, the Scalable Content Access Network. SCAN combines dynamic replica placement with a self-organizing application-level multicast tree to meet client QoS and server resource constraints. It utilizes an underlying distributed object routing and location system (DOLR) as an essential component.Sim ulation results on both flash-crowd-like synthetic workloads and realWeb server traces show that SCAN deploys close to an optimal number of replicas, achieves good load balance, and incurs a small delay and bandwidth penalty for update multicast relative to static replica placement on IP multicast. We envision that SCAN could enhance a number of different applications, such as content distribution and peer-to-peer file sharing.
---
paper_title: Complex Queries in DHT-based Peer-to-Peer Networks

paper_content:

Recently a new generation of P2P systems, offering distributed hash table (DHT) functionality, have been proposed. These systems greatly improve the scalability and exact-match accuracy of P2P systems, but offer only the exact-match query facility. This paper outlines a research agenda for building complex query facilities on top of these DHT-based P2P systems. We describe the issues involved and outline our research plan and current status.
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paper_title: Analysis of the evolution of peer-to-peer systems

paper_content:

In this paper, we give a theoretical analysis of peer-to-peer (P2P) networks operating in the face of concurrent joins and unexpected departures. We focus on Chord, a recently developed P2P system that implements a distributed hash table abstraction, and study the process by which Chord maintains its distributed state as nodes join and leave the system. We argue that traditional performance measures based on run-time are uninformative for a continually running P2P network, and that the rate at which nodes in the network need to participate to maintain system state is a more useful metric. We give a general lower bound on this rate for a network to remain connected, and prove that an appropriately modified version of Chord's maintenance rate is within a logarithmic factor of the optimum rate.
---
paper_title: Observations on the Dynamic Evolution of Peer-to-Peer Networks

paper_content:

A fundamental theoretical challenge in peer-to-peer systems is proving statements about the evolution of the system while nodes are continuously joining and leaving. Because the system will operate for an infinite time, performance measures based on runtime are uninformative; instead, we must study the rate at which nodes consume resources in order to maintain the system state.This "maintenance bandwidth" depends on the rate at which nodes tend to enter and leave the system. In this paper, we formalize this dependence. Having done so, we analyze the Chord peer-to-peer protocol. We show that Chord's maintenance bandwidth to handle concurrent node arrivals and departures is near optimal, exceeding the lower bound by only a logarithmic factor. We also outline and analyze an algorithm that converges to a correct routing state from an arbitrary initial condition.
---
paper_title: Exploring the Design Space of Distributed and Peer-to-Peer Systems: Comparing the Web, TRIAD, and Chord/CFS

paper_content:

Despite the existence of many peer-to-peer systems, some of their design choices and implications are not well understood. This paper compares several distributed and peer-to-peer systems by evaluating a key set of architectural decisions: naming, addressing, routing, topology, and name lookup. Using the World Wide Web, Triad, and Chord/CFS as examples, we illustrate how different architectural choices impact availability, redundancy, security, and fault-tolerance.
---
paper_title: A Survey of Peer-to-Peer Security Issues

paper_content:

Peer-to-peer (p2p) networking technologies have gained popularity as a mechanism for users to share files without the need for centralized servers. A p2p network provides a scalable and fault-tolerant mechanism to locate nodes anywhere on a network without maintaining a large amount of routing state. This allows for a variety of applications beyond simple file sharing. Examples include multicast systems, anonymous communications systems, and web caches. We survey security issues that occur in the underlying p2p routing protocols, as well as fairness and trust issues that occur in file sharing and other p2p applications. We discuss how techniques, ranging from cryptography, to random network probing, to economic incentives, can be used to address these problems.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: Exploring the Design Space of Distributed and Peer-to-Peer Systems: Comparing the Web, TRIAD, and Chord/CFS

paper_content:

Despite the existence of many peer-to-peer systems, some of their design choices and implications are not well understood. This paper compares several distributed and peer-to-peer systems by evaluating a key set of architectural decisions: naming, addressing, routing, topology, and name lookup. Using the World Wide Web, Triad, and Chord/CFS as examples, we illustrate how different architectural choices impact availability, redundancy, security, and fault-tolerance.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: Wide-area cooperative storage with CFS

paper_content:

The Cooperative File System (CFS) is a new peer-to-peer read-only storage system that provides provable guarantees for the efficiency, robustness, and load-balance of file storage and retrieval. CFS does this with a completely decentralized architecture that can scale to large systems. CFS servers provide a distributed hash table (DHash) for block storage. CFS clients interpret DHash blocks as a file system. DHash distributes and caches blocks at a fine granularity to achieve load balance, uses replication for robustness, and decreases latency with server selection. DHash finds blocks using the Chord location protocol, which operates in time logarithmic in the number of servers.CFS is implemented using the SFS file system toolkit and runs on Linux, OpenBSD, and FreeBSD. Experience on a globally deployed prototype shows that CFS delivers data to clients as fast as FTP. Controlled tests show that CFS is scalable: with 4,096 servers, looking up a block of data involves contacting only seven servers. The tests also demonstrate nearly perfect robustness and unimpaired performance even when as many as half the servers fail.
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paper_title: Efficient dispersal of information for security, load balancing, and fault tolerance

paper_content:

An Information Dispersal Algorithm (IDA) is developed that breaks a file F of length L = u F u into n pieces F i , l ≤ i ≤ n , each of length u F i u = L / m , so that every m pieces suffice for reconstructing F . Dispersal and reconstruction are computationally efficient. The sum of the lengths u F i u is ( n / m ) · L . Since n / m can be chosen to be close to l, the IDA is space efficient. IDA has numerous applications to secure and reliable storage of information in computer networks and even on single disks, to fault-tolerant and efficient transmission of information in networks, and to communications between processors in parallel computers. For the latter problem provably time-efficient and highly fault-tolerant routing on the n -cube is achieved, using just constant size buffers.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: A Survey of Peer-to-Peer Security Issues

paper_content:

Peer-to-peer (p2p) networking technologies have gained popularity as a mechanism for users to share files without the need for centralized servers. A p2p network provides a scalable and fault-tolerant mechanism to locate nodes anywhere on a network without maintaining a large amount of routing state. This allows for a variety of applications beyond simple file sharing. Examples include multicast systems, anonymous communications systems, and web caches. We survey security issues that occur in the underlying p2p routing protocols, as well as fairness and trust issues that occur in file sharing and other p2p applications. We discuss how techniques, ranging from cryptography, to random network probing, to economic incentives, can be used to address these problems.
---
paper_title: The Steganographic File System

paper_content:

Users of some systems are at risk of being compelled to disclose their keys or other private data, and this risk could be mitigated if access control mechanisms supported an element of plausible deniability. However, existing plausible deniability mechanisms, such as the one-time pad, are of rather limited scope.
---
paper_title: Anonymizing Censorship Resistant Systems

paper_content:

In this paper we propose a new Peer-to-Peer architecture for a censorship resistant system with user, server and active-server document anonymity as well as efficient document retrieval. The retrieval service is layered on top of an existing Peer-to-Peer infrastructure, which should facilitate its implementation. The key idea is to separate the role of document storers from the machines visible to the users, which makes each individual part of the system less prone to attacks, and therefore to censorship.
---
paper_title: Scan: A dynamic, scalable, and efficient content distribution network

paper_content:

We present SCAN, the Scalable Content Access Network. SCAN combines dynamic replica placement with a self-organizing application-level multicast tree to meet client QoS and server resource constraints. It utilizes an underlying distributed object routing and location system (DOLR) as an essential component.Sim ulation results on both flash-crowd-like synthetic workloads and realWeb server traces show that SCAN deploys close to an optimal number of replicas, achieves good load balance, and incurs a small delay and bandwidth penalty for update multicast relative to static replica placement on IP multicast. We envision that SCAN could enhance a number of different applications, such as content distribution and peer-to-peer file sharing.
---
paper_title: Open Problems in Data-Sharing Peer-to-Peer Systems

paper_content:

In a Peer-To-Peer (P2P) system, autonomous computers pool their resources (e.g., files, storage, compute cycles) in order to inexpensively handle tasks that would normally require large costly servers. The scale of these systems, their "open nature," and the lack of centralized control pose difficult performance and security challenges. Much research has recently focused on tackling some of these challenges; in this paper, we propose future directions for research in P2P systems, and highlight problems that have not yet been studied in great depth. We focus on two particular aspects of P2P systems - search and security - and suggest several open and important research problems for the community to address.
---
paper_title: Onion Routing for Anonymous and Private Internet Connections

paper_content:

Abstract : Preserving privacy means not only hiding the content of messages, but also hiding who is talking to whom (traffic analysis). Much like a physical envelope, the simple application of cryptography within a packet-switched network hides the messages being sent, but can reveal who is talking to whom, and how often. Onion Routing is a general purpose infrastructure for private communication over a public network [8, 9, 4]. It provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. The connections are bidirectional, near real-time, and can be used for both connection-based and connectionless traffic. Onion Routing interfaces with off the shelf software and systems through specialized proxies, making it easy to integrate into existing systems. Prototypes have been running since July 1997. As of this article's publication, the prototype network is processing more than 1 million Web connections per month from more than six thousand IP addresses in twenty countries and in all six main top level domains. [7]
---
paper_title: Introducing Tarzan, a Peer-to-Peer Anonymizing Network Layer

paper_content:

We introduce Tarzan, a peer-to-peer anonymous network layer that provides generic IP forwarding. Unlike prior anonymizing layers, Tarzan is flexible, transparent, decentralized, and highly scalable.Tarzan achieves these properties by building anonymous IP tunnels between an open-ended set of peers. Tarzan can provide anonymity to existing applications, such as web browsing and file sharing, without change to those applications. Performance tests show that Tarzan imposes minimal overhead over a corresponding non-anonymous overlay route.
---
paper_title: Untraceable electronic mail, return addresses, and digital pseudonyms

paper_content:

A technique based on public key cryptography is presented that allows an electronic mail system to hide who a participant communicates with as well as the content of the communication - in spite of an unsecured underlying telecommunication system. The technique does not require a universally trusted authority. One correspondent can remain anonymous to a second, while allowing the second to respond via an untraceable return address. The technique can also be used to form rosters of untraceable digital pseudonyms from selected applications. Applicants retain the exclusive ability to form digital signatures corresponding to their pseudonyms. Elections in which any interested party can verify that the ballots have been properly counted are possible if anonymously mailed ballots are signed with pseudonyms from a roster of registered voters. Another use allows an individual to correspond with a record-keeping organization under a unique pseudonym, which appears in a roster of acceptable clients.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: Anonymizing Censorship Resistant Systems

paper_content:

In this paper we propose a new Peer-to-Peer architecture for a censorship resistant system with user, server and active-server document anonymity as well as efficient document retrieval. The retrieval service is layered on top of an existing Peer-to-Peer infrastructure, which should facilitate its implementation. The key idea is to separate the role of document storers from the machines visible to the users, which makes each individual part of the system less prone to attacks, and therefore to censorship.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: Scan: A dynamic, scalable, and efficient content distribution network

paper_content:

We present SCAN, the Scalable Content Access Network. SCAN combines dynamic replica placement with a self-organizing application-level multicast tree to meet client QoS and server resource constraints. It utilizes an underlying distributed object routing and location system (DOLR) as an essential component.Sim ulation results on both flash-crowd-like synthetic workloads and realWeb server traces show that SCAN deploys close to an optimal number of replicas, achieves good load balance, and incurs a small delay and bandwidth penalty for update multicast relative to static replica placement on IP multicast. We envision that SCAN could enhance a number of different applications, such as content distribution and peer-to-peer file sharing.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: Anonymizing Censorship Resistant Systems

paper_content:

In this paper we propose a new Peer-to-Peer architecture for a censorship resistant system with user, server and active-server document anonymity as well as efficient document retrieval. The retrieval service is layered on top of an existing Peer-to-Peer infrastructure, which should facilitate its implementation. The key idea is to separate the role of document storers from the machines visible to the users, which makes each individual part of the system less prone to attacks, and therefore to censorship.
---
paper_title: Analyzing the economic efficiency of eBay-like online reputation reporting mechanisms

paper_content:

This paper introduces a model for analyzing marketplaces, such as eBay, which rely on binary reputation mechanisms for quality signaling and quality control. In our model sellers keep their actual quality private and choose what quality to advertise. The reputation mechanism is primarily used to determine whether sellers advertise truthfully. Buyers may exercise some leniency when rating sellers, which needs to be compensated by corresponding strictness when judging sellers'feedback profiles. It is shown that, the more lenient buyers are when rating sellers, the more likely it is that sellers will find it optimal to settle down to steady-state quality levels, as opposed to oscillating between good quality and bad quality. Furthermore, the fairness of the market outcome is determined by the relationship between rating leniency and strictness when assessing a seller's feedback profile. If buyers judge sellers too strictly (relative to how leniently they rate) then, at steady state, sellers will be forced to understate their true quality. On the other hand, if buyers judge too leniently then sellers can get away with consistently overstating their true quality. An optimal judgment rule, which results in outcomes where at steady state buyers accurately estimate the true quality of sellers, is analytically derived. However, it is argued that this optimal rule depends on several system parameters, which are difficult to estimate from the information that marketplaces, such as eBay, currently make available to their members. It is therefore questionable to what extent unsophisticated buyers are capable of deriving and applying it correctly in actual settings.
---
paper_title: A Survey of Peer-to-Peer Security Issues

paper_content:

Peer-to-peer (p2p) networking technologies have gained popularity as a mechanism for users to share files without the need for centralized servers. A p2p network provides a scalable and fault-tolerant mechanism to locate nodes anywhere on a network without maintaining a large amount of routing state. This allows for a variety of applications beyond simple file sharing. Examples include multicast systems, anonymous communications systems, and web caches. We survey security issues that occur in the underlying p2p routing protocols, as well as fairness and trust issues that occur in file sharing and other p2p applications. We discuss how techniques, ranging from cryptography, to random network probing, to economic incentives, can be used to address these problems.
---
paper_title: A reputation system for peer-to-peer networks

paper_content:

We investigate the design of a reputation system for decentralized unstructured P2P networks like Gnutella. Having reliable reputation information about peers can form the basis of an incentive system and can guide peers in their decision making (e.g., who to download a file from). The reputation system uses objective criteria to track each peer's contribution in the system and allows peers to store their reputations locally. Reputation are computed using either of the two schemes, debit-credit reputation computation (DCRC) and credit-only reputation computation (CORC). Using a reputation computation agent (RCA), we design a public key based mechanism that periodically updates the peer reputations in a secure, light-weight, and partially distributed manner. We evaluate using simulations the performance tradeoffs inherent in the design of our system.
---
paper_title: OceanStore: an architecture for global-scale persistent storage

paper_content:

OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development.
---
paper_title: A game theoretic framework for incentives in P2P systems

paper_content:

Peer-to-peer (P2P) networks are self-organizing, distributed systems, with no centralized authority or infrastructure. Because of the voluntary participation, the availability of resources in a P2P system can be highly variable and unpredictable. We use ideas from game theory to study the interaction of strategic and rational peers, and propose a differential service-based incentive scheme to improve the system's performance.
---
paper_title: Exchange-based incentive mechanisms for peer-to-peer file sharing

paper_content:

Performance of peer-to-peer resource sharing networks depends upon the level of cooperation of the participants. To date, cash-based systems have seemed too complex, while lighter-weight credit mechanisms have not provided strong incentives for cooperation. We propose exchange-based mechanisms that provide incentives for cooperation in peer-to-peer file sharing networks. Peers give higher service priority to requests from peers that can provide a simultaneous and symmetric service in return. We generalize this approach to n-way exchanges among rings of peers and present a search algorithm for locating such rings. We have used simulation to analyze the effect of exchanges on performance. Our results show that exchange-based mechanisms can provide strong incentives for sharing, offering significant improvements in service times for sharing users compared to free-riders, without the problems and complexity of cash- or credit-based systems.
---
paper_title: Scan: A dynamic, scalable, and efficient content distribution network

paper_content:

We present SCAN, the Scalable Content Access Network. SCAN combines dynamic replica placement with a self-organizing application-level multicast tree to meet client QoS and server resource constraints. It utilizes an underlying distributed object routing and location system (DOLR) as an essential component.Sim ulation results on both flash-crowd-like synthetic workloads and realWeb server traces show that SCAN deploys close to an optimal number of replicas, achieves good load balance, and incurs a small delay and bandwidth penalty for update multicast relative to static replica placement on IP multicast. We envision that SCAN could enhance a number of different applications, such as content distribution and peer-to-peer file sharing.
---
paper_title: Peer-to-Peer Resource Trading in a Reliable Distributed System

paper_content:

Peer-to-peer architectures can be used to build a robust, fault tolerant infrastructure for important services. One example is a peer-to-peer data replication system, in which digital collections are protected from failure by being replicated at multiple peers. We argue that such community-based redundancy, in which multiple sites contribute resources to build a fault-tolerant system, is an important application of peer-to-peer networking. In such a system, there must be flexible, effective techniques for managing resource allocation. We propose data trading, a mechanism where a site acquires remote resources in the community by trading away its own local resources. We discuss the application of data trading to the data replication problem, and examine other applications of trading. A general trading infrastructure is a valuable part of a peer-to-peer, community-based redundancy system.
---
paper_title: A Survey of Peer-to-Peer Security Issues

paper_content:

Peer-to-peer (p2p) networking technologies have gained popularity as a mechanism for users to share files without the need for centralized servers. A p2p network provides a scalable and fault-tolerant mechanism to locate nodes anywhere on a network without maintaining a large amount of routing state. This allows for a variety of applications beyond simple file sharing. Examples include multicast systems, anonymous communications systems, and web caches. We survey security issues that occur in the underlying p2p routing protocols, as well as fairness and trust issues that occur in file sharing and other p2p applications. We discuss how techniques, ranging from cryptography, to random network probing, to economic incentives, can be used to address these problems.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: Incentives build robustness in BitTorrent

paper_content:

The BitTorrent file distribution system uses tit-fortat as a method of seeking pareto efficiency. It achieves a higher level of robustness and resource utilization than any currently known cooperative technique. We explain what BitTorrent does, and how economic methods are used to achieve that goal. 1 What BitTorrent Does When a file is made available using HTTP, all upload cost is placed on the hosting machine. With BitTorrent, when multiple people are downloading the same file at the same time, they upload pieces of the file to each other. This redistributes the cost of upload to downloaders, (where it is often not even metered), thus making hosting a file with a potentially unlimited number of downloaders affordable. Researchers have attempted to find practical techniqes to do this before[3]. It has not been previously deployed on a large scale because the logistical and robustness problems are quite difficult. Simply figuring out which peers have what parts of the file and where they should be sent is difficult to do without incurring a huge overhead. In addition, real deployments experience very high churn rates. Peers rarely connect for more than a few hours, and frequently for only a few minutes [4]. Finally, there is a general problem of fairness [1]. The total download rate across all downloaders must, of mathematical necessity, be equal to the total upload rate. The strategy for allocating upload which seems most likely to make peers happy with their download rates is to make each peer’s download rate be proportional to their upload rate. In practice it’s very difficult to keep peer download rates from sometimes dropping to zero by chance, much less make upload and download rates be correlated. We will explain how BitTorrent solves all of these problems well. 1.1 BitTorrent Interface BitTorrent’s interface is almost the simplest possible. Users launch it by clicking on a hyperlink to the file they wish to download, and are given a standard “Save As” dialog, followed by a download progress dialog which is mostly notable for having an upload rate in addition to a download rate. This extreme ease of use has contributed greatly to BitTorrent’s adoption, and may even be more important than, although it certainly complements, the performance and cost redistribution features which are described in this paper.
---
paper_title: Publius: A robust, tamper-evident, censorship-resistant, web publishing system

paper_content:

We describe a system that we have designed and implemented for publishing content on the web. Our publishing scheme has the property that it is very difficult for any adversary to censor or modify the content. In addition, the identity of the publisher is protected once the content is posted. Our system differs from others in that we provide tools for updating or deleting the published content, and users can browse the content in the normal point and click manner using a standard web browser and a client-side proxy that we provide. All of our code is freely available.
---
paper_title: Freenet: A Distributed Anonymous Information Storage and Retrieval System

paper_content:

We describe Freenet, an adaptive peer-to-peer network application that permits the publication, replication, and retrieval of data while protecting the anonymity of both authors and readers. Freenet operates as a network of identical nodes that collectively pool their storage space to store data files and cooperate to route requests to the most likely physical location of data. No broadcast search or centralized location index is employed. Files are referred to in a location-independent manner, and are dynamically replicated in locations near requestors and deleted from locations where there is no interest. It is infeasible to discover the true origin or destination of a file passing through the network, and difficult for a node operator to determine or be held responsible for the actual physical contents of her own node.
---
paper_title: The Free Haven Project: Distributed Anonymous Storage Service

paper_content:

A resistance-to-current converter in which a sensing resistor, such as a resistance thermometer bulb for sensing changes in temperature, forms an arm in a resistance bridge which is periodically excited by a switching circuit interposed between a power supply and the input junctions of the bridge. The voltage produced at the output junctions of the bridge during the "on" and "off" excitation states are separately detected. The detected signal obtained in the "off" state is subtracted from that obtained in the "on" state to produce an output signal from which there is eliminated the error component resulting from a leakage resistance path coupled to said sensing resistor.
---
paper_title: Semantic Overlay Clusters within Super-Peer Networks

paper_content:

When joining information provider peers to a peer-to-peer network, an arbitrary distribution is sub-optimal. In fact, clustering peers by their characteristics, enhances search and integration significantly. Currently super-peer networks, such as the Edutella network, provide no sophisticated means for such a semantic clustering of peers. We introduce the concept of semantic overlay clusters (SOC) for super-peer networks enabling a controlled distribution of peers to clusters. In contrast to the recently announced semantic overlay network approach designed for flat, pure peer-to-peer topologies and for limited meta data sets, such as simple filenames, we allow a clustering of complex heterogeneous schemes known from relational databases and use advantages of super-peer networks, such as efficient search and broadcast of messages. Our approach is based on predefined policies defined by human experts. Based on such policies a fully decentralized broadcast-and matching approach distributes the peers automatically to super-peers. Thus we are able to automate the integration of information sources in super-peer networks and reduce flooding of the network with messages.
---
paper_title: Locality Aware Mechanisms for Large-scale Networks

paper_content:

Recent advances in decentralized object location and routing (DOLR) systems provide an attractive platform for wide-area network applications. These systems, also referred to as distributed hashtables, provide routing and location algorithms which scale logarithmically with the size of the network. In this paper, we contend that many properties of these systems are not yet well understood in the context of deployed large-scale networks. Specifically, we identify the property of locality-awareness and show how locality-aware design mechanisms play a positive role in providing greater scalability in wide-area networks.
---
paper_title: A Peer-to-Peer Architecture for Distributed Knowledge Management

paper_content:

Most of the knowledge management systems of complex organizations are based on technological architectures that are in contradiction with the social processes of knowledge creation. In particular, centralized architectures are adopted to manage a process that is intrinsically distributed. In this paper, assuming a Distributed approach to Knowledge Management (DKM), is proposed that technological and social architectures must be reciprocally consistent. Moreover, in the domain of Knowledge Management, technological architectures should be designed in order to support the interplay between two qualitatively different processes: the autonomous management of knowledge of individuals and groups - here called Knowledge Nodes (KNs) -, and the coordination required in order to exchange knowledge among them. Finally a peer to peer architecture to support knowledge exchange across distributed and autonomous KNs is presented.
---
paper_title: G.: Ontology-Addressable Contents in P2P Networks

paper_content:

A critical issue for P2P systems is to perform an effective content retrieval taking into account semantic properties of what is searched. Important requirements to be considered for knowledge sharing in P2P systems are related to the inherent dynamism of the P2P context demanding for a decentralized sharing and administration of knowledge and to the role of Semantic Web techniques to support data semantics representation and rich query languages for content retrieval. In this paper, we describe a comprehensive framework, called H, for ontologyaddressable contents in P2P systems, which is composed by a knowledge infrastructure layer (Helios) and a communication infrastructure layer (Hermes). The H framework proposes to build an overlay network among peers in which each peer maintains a peer ontology describing its knowledge of the network. For query routing, the topology of the overlay network mirrors the semantic neighborhood of the peers given by the semantic relationships among the ontologies they own.
---
paper_title: A Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems

paper_content:

We consider a collaborative application scenario in Open Hypermedia Systems. We describe a semantic search algorithm to discover semantically equivalent or related resources across distributed link databases, otherwise known as linkbases. Our approach differs from traditional crawler based search mechanisms because it relies on clustering of semantically related entities. It creates clusters of related semantic entities to expedite the search for resources in a random network. It uses a distance-vector based heuristic to guide the search. Our results confirm that the algorithm yields high search efficiency in collaborative environments where the change in content published by each participant is rapid and random.
---

Title: A Survey of Peer-to-Peer Content Distribution Technologies

Section 1: INTRODUCTION
Description 1: Introduce the background, motivation, and objectives for surveying peer-to-peer content distribution technologies.

Section 2: Defining Peer-to-Peer Computing
Description 2: Define the basic concepts of peer-to-peer computing and discuss various definitions found in the literature.

Section 3: Peer-to-Peer and Grid Computing
Description 3: Discuss the similarities and differences between peer-to-peer and grid computing, and explore their potential convergence.

Section 4: Classification of Peer-to-Peer Applications
Description 4: Classify peer-to-peer systems into different application categories such as communication and collaboration, distributed computation, and content distribution.

Section 5: Peer-to-Peer Content Distribution
Description 5: Discuss the fundamentals of peer-to-peer content distribution systems and categorize them based on their application goals and complexity.

Section 6: ANALYSIS FRAMEWORK
Description 6: Present a framework for analyzing peer-to-peer content distribution systems by identifying key features and design aspects affecting nonfunctional properties.

Section 7: PEER-TO-PEER DISTRIBUTED OBJECT LOCATION AND ROUTING
Description 7: Examine various routing and location mechanisms employed by peer-to-peer content distribution systems and their impact on system attributes.

Section 8: CONTENT CACHING, REPLICATION AND MIGRATION
Description 8: Discuss content caching, replication, and migration techniques and how they improve availability, performance, and censorship resistance.

Section 9: SECURITY
Description 9: Analyze security measures in peer-to-peer content distribution systems, including secure storage, secure routing, access control, and identity management.

Section 10: PROVISIONS FOR ANONYMITY
Description 10: Explore approaches used for ensuring anonymity in peer-to-peer content distribution systems.

Section 11: PROVISIONS FOR DENIABILITY
Description 11: Discuss methods to provide deniability of content being stored and transferred within peer-to-peer systems.

Section 12: INCENTIVE MECHANISMS AND ACCOUNTABILITY
Description 12: Review various incentive mechanisms and accountability methods used to encourage cooperation and balanced resource usage in peer-to-peer systems.

Section 13: RESOURCE MANAGEMENT CAPABILITIES
Description 13: Describe resource management features in peer-to-peer content distribution systems, including content deletion, update, versioning, and bandwidth management.

Section 14: SEMANTIC GROUPING OF INFORMATION
Description 14: Present approaches for semantic grouping and organization of content in peer-to-peer networks to improve search efficiency and result quality.

Section 15: CONCLUSIONS
Description 15: Summarize the key points, current trends, and open research problems in peer-to-peer content distribution technologies.