Peer-to-Peer. Harnessing the Power of Disruptive Technologies (e-book) Chorzów

The term "peer-to-peer" has come to be applied to networks that expect end users to contribute their own files, computing time, or other resources to some shared project. Even more interesting than the systems technical underpinnings are their socially disruptive potential: in various ways they return content, choice, and control to ordinary users.While this book is mostly about the technical promise of peer-to-peer, we also talk about its exciting social promise. Communities have been forming on the Internet for a long time, but they have been limited by the flat interactive qualities of email and Network newsgroups. People can exchange recommendations and ideas over these media, but have great difficulty commenting on each others postings, structuring information, performing searches, or creating summaries. If tools provided ways to organize information intelligently, and if each person could serve up his or her own data and retrieve others data, the possibilities for collaboration would take off. Peer-to-peer technologies along with metadata could enhance almost any group of people who share an interest--technical, cultural, political, medical, you name it.This book presents the goals that drive the developers of the best-known peer-to-peer systems, the problems theyve faced, and the technical solutions theyve found. Learn here the essentials of peer-to-peer from leaders of the field: Nelson Minar and Marc Hedlund of Freenet, on gateways between peer-to-peer systems Youll find information on the latest and greatest systems as well as upcoming efforts in this book. Spis treści: Peer to Peer Preface Some context and a definition How this book came into being Contents of this book Peer-to-peer web site Wed like to hear from you I. Context and Overview 1. A Network of Peers: Peer-to-Peer Models Through the History of the Internet A revisionist history of peer-to-peer (1969-1995) Usenet DNS The network model of the Internet explosion (1995-1999) The switch to client/server The breakdown of cooperation Spam: Uncooperative people The TCP rate equation: Cooperative protocols Firewalls, dynamic IP, NAT: The end of the open network Asymmetric bandwidth Observations on the current crop of peer-to-peer applications (2000) Authoring is not the same as publishing Decentralization Abusing port 80 Peer-to-peer prescriptions (2001-?) Technical solutions: Return to the old Internet Social solutions: Engineer polite behavior Conclusions 2. Listening to Napster Resource-centric addressing for unstable environments Peer-to-peer is as peer-to-peer does The veil is pierced Real solutions to real problems Whos in and whos out? Peer-to-peer is a horseless carriage Follow the users Users reward simplicity Listen to Napster Its the applications, stupid Decentralization is a tool, not a goal Wheres the content? PCs are the dark matter of the Internet Promiscuous computers Nothing succeeds like address, or, DNS isnt the only game in town An explosion of protocols An economic rather than legal challenge All you can eat Yesterdays technology at tomorrows prices, two days late 30 million Britney fans does not a revolution make Peer-to-peer architecture and second-class status Users as consumers, users as providers New winners and losers 3. Remaking the Peer-to-Peer Meme From business models to meme maps A success story: From free software to open source The current peer-to-peer meme map The new peer-to-peer meme map File sharing: Napster and successors Mixing centralization and decentralization: Usenet, email, and IP routing Maximizing use of far-flung resources: Distributed computation Immediate information sharing: The new instant messaging services The writable Web Web services and content syndication Peer-to-peer and devices Strategic positioning and core competencies 4. The Cornucopia of the Commons Ways to fill shared databases CDDB: A case study in how to get a manually created database Napster: Harnessing the power of personal selfishness The commons II. Projects 5. SETI@home Radio SETI How SETI@home works Trials and tribulations Human factors The worlds most powerful computer The peer-to-peer paradigm 6. Jabber: Conversational Technologies Conversations and peers Evolving toward the ideal Jabber is created The centrality of XML Pieces of the infrastructure Identity Presence Roster Architecture Protocols Browsing Conversation management Conclusion 7. Mixmaster Remailers A simple example of remailers Onion routing How Type 2 remailers differ from Type 1 remailers General discussion 8. Gnutella Gnutella in a gnutshell A brief history Gnutellas first breath Open source to the rescue What makes Gnutella different? Gnutella works like the real world A Gnutella cocktail party A client/server cocktail party Client/server means control, and control means responsibility The client is the server is the network Distributed intelligence Different from Freenet Gnutellas communication system Message-based, application-level routing TCP broadcast Message broadcasting Dynamic routing Lossy transmission over reliable TCP Organizing Gnutella Placing nodes on the network Gnutellas analogues The Gnutella horizon Cellular telephony and the Gnutella network Ethernet Cultivating the Gnutella network Gnutellas traffic problems Host caches Returning the network to its natural state Private Gnutella networks Reducing broadcasts makes a significant impact The policy debates Napster wars Anonymity and peer-to-peer Gnutella pseudoanonymity Downloads, now in the privacy of your own direct connection Anonymous Gnutella chat Next-generation peer-to-peer file-sharing technologies Gnutellas effects 9. Freenet Requests Detail of requests The data store Keys Key types Content Hash Keys (CHKs) Keyword Signed Keys (KSKs) Signature Verification Keys (SVKs) Keys and redirects Conclusions 10. Red Rover Architecture The hub The clients The subscribers Client life cycle Putting low-tech weaknesses into perspective Acknowledgments 11. Publius Why censorship-resistant anonymous publishing? Publius and other systems in this book System architecture Cryptography fundamentals Encryption and decryption Secret sharing Hash functions Publius operations Publish operation Retrieve operation Update operation Delete operation Publius implementation User interface Server software Client software Publius MIME type Publius in a nutshell 12. Free Haven Privacy in data-sharing systems Reliability with anonymity Anonymity for anonymous storage Partial anonymity The design of Free Haven Elements of the system Storage Publication Retrieval Share expiration Document revocation Trading Receipts Accountability and the buddy system Communications channel Reputation system Introducers Implementation status Attacks on Free Haven Attacks on documents or the servnet Attacks on the reputation system Attacks on anonymity An analysis of anonymity Future work Conclusion Acknowledgments III. Technical Topics 13. Metadata Data about data Metadata lessons from the Web Resource description Searching Resources and relationships: A historical overview Foundations of resource description: Unique identifiers A contrasting evolution: MP3 and the metadata marketplace Conclusion 14. Performance A note on terminology Why performance matters Bandwidth barriers Its a small, small world An excursion into graph theory The small-world model Case study 1: Freenet Initial experiments Simulating growth Simulating fault tolerance Link distribution in Freenet The impact of free riding Scalability Case study 2: Gnutella Initial experiments Fault tolerance and link distribution in Gnutella The impact of free riding Scalability Conclusions Acknowledgments 15. Trust Trust in real life, and its lessons for computer networks Trusting downloaded software Message digest functions Digital signatures Digital certificates Signature verification Open source software Sandboxing and wrappers Trust in censorship-resistant publishing systems Publius in a nutshell Risks involved in web server logging Anonymizing proxies Censorship in Publius Using the Update mechanism to censor Publius proxy volunteers Third-party trust issues in Publius Other anonymity tools SSL Mix networks Crowds Denial of service attacks Quota systems CPU-based payment schemes Anonymous e-cash payment schemes Legal and physical attacks Trust in other systems Mojo Nation and Free Haven The Eternity Service Eternity Usenet File-sharing systems Napster Gnutella Freenet Content certification Trust and search engines Distributed search engines Deniability Conclusions 16. Accountability The difficulty of accountability Special problems posed by peer-to-peer systems Peer-to-peer models and their impacts on accountability Purposes of micropayments and reputation systems Junk mail as a resource allocation problem Pseudonymity and its consequences Problems with pseudospoofing and possible defenses Reputation for saleSOLD! Common methods for dealing with flooding and DoS attacks Caching and mirroring Active caching and mirroring Micropayment schemes Varieties of micropayments or digital cash Nonfungible micropayments Extended types of nonfungible micropayments Nonparallelizable work functions Fungible micropayments Freeloading Fungible payments for accountability Micropayment digital cash schemes Making money off others work Anonymous macropayment digital cash schemes The use and effectiveness of micropayments in peer-to-peer systems Identity-based payment policies General considerations in an economic analysis of micropayment design Moderating security levels: An accountability slider Reputations Early reputation systems online Codifying reputation on a wide scale: The PGP web of trust Who will moderate the moderators: Slashdot Reputations worth real money: eBay A reputation system that resists pseudospoofing: Advogato System successes and failures Scoring systems Attacks and adversaries Aspects of a scoring system Collecting ratings Bootstrapping Personalizing reputation searches Scoring algorithms Privacy and information leaks Decentralizing the scoring system Multiple trusted parties True decentralization A case study: Accountability in Free Haven Micropayments The difficulty of distributed systems: How to exchange micropayments among peers Micropayments in the Free Haven context Reputation systems Other considerations from the case study Conclusion Acknowledgments 17. Reputation Examples of using the Reputation Server Reputation domains, entities, and multidimensional reputations Identity as an element of reputation Interface to the marketplace Scoring system Reputation metrics Credibility Interdomain sharing Bootstrapping Long-term vision Central Reputation Server versus distributed Reputation Servers Summary 18. Security Groove versus email Why secure email is a failure The solution: A Groove shared space Security characteristics of a shared space Mutually-trusting shared spaces Anatomy of a mutually-trusting shared space The key to mutual trust Mutually-suspicious shared spaces Message fanout Fetching lost messages Shared space formation and trusted authentication Inviting people into shared spaces The New-Member-Added delta message Key versioning and key dependencies Central control and local autonomy Practical security for real-world collaboration Taxonomy of Groove keys 19. Interoperability Through Gateways Why unification? Why not an ÜberNetwork? Why not an ÜberClient? Why not just use XML? One network with a thousand faces Well-known networks and their roles Freenet Gnutella Mojo Nation Free Haven and Publius Problems creating gateways Problems with inserts Problems with requests Freenet Gnutella Mojo Nation Publius Free Haven Gateway implementation Existing projects Conclusion Acknowledgments 20. Afterword Precedents and parries Who gets to innovate? A clean sweep? A. Directory of Peer-to-Peer Projects B. Contributors Index Copyright