A Censorship Resistant Web Annotations System Using IPFS and Ethereum
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
The Internet and Drug Markets
INSIGHTS EN ISSN THE INTERNET AND DRUG MARKETS 2314-9264 The internet and drug markets 21 The internet and drug markets EMCDDA project group Jane Mounteney, Alessandra Bo and Alberto Oteo 21 Legal notice This publication of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) is protected by copyright. The EMCDDA accepts no responsibility or liability for any consequences arising from the use of the data contained in this document. The contents of this publication do not necessarily reflect the official opinions of the EMCDDA’s partners, any EU Member State or any agency or institution of the European Union. Europe Direct is a service to help you find answers to your questions about the European Union Freephone number (*): 00 800 6 7 8 9 10 11 (*) The information given is free, as are most calls (though some operators, phone boxes or hotels may charge you). More information on the European Union is available on the internet (http://europa.eu). Luxembourg: Publications Office of the European Union, 2016 ISBN: 978-92-9168-841-8 doi:10.2810/324608 © European Monitoring Centre for Drugs and Drug Addiction, 2016 Reproduction is authorised provided the source is acknowledged. This publication should be referenced as: European Monitoring Centre for Drugs and Drug Addiction (2016), The internet and drug markets, EMCDDA Insights 21, Publications Office of the European Union, Luxembourg. References to chapters in this publication should include, where relevant, references to the authors of each chapter, together with a reference to the wider publication. For example: Mounteney, J., Oteo, A. and Griffiths, P. -
IPFS and Friends: a Qualitative Comparison of Next Generation Peer-To-Peer Data Networks Erik Daniel and Florian Tschorsch
1 IPFS and Friends: A Qualitative Comparison of Next Generation Peer-to-Peer Data Networks Erik Daniel and Florian Tschorsch Abstract—Decentralized, distributed storage offers a way to types of files [1]. Napster and Gnutella marked the beginning reduce the impact of data silos as often fostered by centralized and were followed by many other P2P networks focusing on cloud storage. While the intentions of this trend are not new, the specialized application areas or novel network structures. For topic gained traction due to technological advancements, most notably blockchain networks. As a consequence, we observe that example, Freenet [2] realizes anonymous storage and retrieval. a new generation of peer-to-peer data networks emerges. In this Chord [3], CAN [4], and Pastry [5] provide protocols to survey paper, we therefore provide a technical overview of the maintain a structured overlay network topology. In particular, next generation data networks. We use select data networks to BitTorrent [6] received a lot of attention from both users and introduce general concepts and to emphasize new developments. the research community. BitTorrent introduced an incentive Specifically, we provide a deeper outline of the Interplanetary File System and a general overview of Swarm, the Hypercore Pro- mechanism to achieve Pareto efficiency, trying to improve tocol, SAFE, Storj, and Arweave. We identify common building network utilization achieving a higher level of robustness. We blocks and provide a qualitative comparison. From the overview, consider networks such as Napster, Gnutella, Freenet, BitTor- we derive future challenges and research goals concerning data rent, and many more as first generation P2P data networks, networks. -
Privacy Enhancing Technologies 2003 an Analysis of Gnunet And
Privacy Enhancing Technologies 2003 An Analysis of GNUnet and the Implications for Anonymous, Censorship-Resistant Networks Dennis Kügler Federal Office for Information Security, Germany [email protected] 1 Anonymous, Censorship-Resistant Networks • Anonymous Peer-to-Peer Networks – Gnutella • Searching is relatively anonymous • Downloading is not anonymous • Censorship-Resistant Networks – Eternity Service • Distributed storage medium • Attack resistant • Anonymous, Censorship-Resistant Networks – Freenet – GNUnet 2 GNUnet: Obfuscated, Distributed Filesystem Content Hash Key: [H(B),H(E (B))] • H(B) – Content encryption: H(B) – Unambiguous filename: H(E (B)) H(B) • Content replication – Caching while delivering – Based on unambiguous filename • Searchability – Keywords 3 GNUnet: Peer-to-Peer MIX Network • Initiating node – Downloads content • Supplying nodes – Store content unencrypted • Intermediary nodes – Forward and cache encrypted content – Plausible deniability due to encryption • Economic model – Based on credit Query A Priority=20 B – Charge for queries c =c -20 B B - – Pay for responses 4 GNUnet Encoding • DBlocks DBlock DBlock ... DBlock – 1KB of the content – Content hash encrypted • IBlocks IBlock ... IBlock – CHKs of 25 DBlocks – Organized as tree – Content hash encrypted IBlock • RBlock – Description of the content – CHK of the root IBlock RBlock – Keyword encrypted 5 The Attacker Model • Attacker – Controls malicious nodes that behave correctly – Prepares dictionary of interesting keywords – Observes queries and -
TRUST, but VERIFY: WHY the BLOCKCHAIN NEEDS the LAW Kevin Werbach†
TRUST, BUT VERIFY: WHY THE BLOCKCHAIN NEEDS THE LAW Kevin Werbach† ABSTRACT The blockchain could be the most consequential development in information technology since the Internet. Created to support the Bitcoin digital currency, the blockchain is actually something deeper: a novel solution to the age-old human problem of trust. Its potential is extraordinary. Yet, this approach may not promote trust at all without effective governance. Wholly divorced from legal enforcement, blockchain-based systems may be counterproductive or even dangerous. And they are less insulated from the law’s reach than it seems. The central question is not how to regulate blockchains but how blockchains regulate. They may supplement, complement, or substitute for legal enforcement. Excessive or premature application of rigid legal obligations will stymie innovation and forego opportunities to leverage technology to achieve public policy objectives. Blockchain developers and legal institutions can work together. Each must recognize the unique affordances of the other system. DOI: https://doi.org/10.15779/Z38H41JM9N © 2018 Kevin Werbach. † Associate Professor of Legal Studies and Business Ethics, The Wharton School, University of Pennsylvania. Email: [email protected]. Thanks to Dan Hunter for collaborating to develop the ideas that gave rise to this Article, and to Sarah Light, Patrick Murck, and participants in the 2017 Lastowka Cyberlaw Colloquium and 2016 TPRC Conference for comments on earlier drafts. 488 BERKELEY TECHNOLOGY LAW JOURNAL [Vol. 33:487 -
Beaver: a Decentralized Anonymous Marketplace with Secure Reputation
Beaver: A Decentralized Anonymous Marketplace with Secure Reputation Kyle Soska∗ Albert Kwon∗ Nicolas Christin Srinivas Devadas CMU MIT CMU MIT [email protected] [email protected] [email protected] [email protected] Abstract—Amid growing concerns of government surveillance they strive to avail reputation systems with strong privacy and and corporate data sharing, web users increasingly demand tools anonymity guarantees, and have proven to be economically for preserving their privacy without placing trust in a third viable. To achieve the desired anonymity properties, online party. Unfortunately, existing centralized reputation systems need anonymous marketplaces build on a combination of network- to be trusted for either privacy, correctness, or both. Existing level anonymity—often running as Tor hidden services [20] decentralized approaches, on the other hand, are either vulner- or i2p “eep sites” [3]—and payment-level anonymity, using able to Sybil attacks, present inconsistent views of the network, or leak critical information about the actions of their users. pseudonymous digital payment systems such as Bitcoin [36]. In this paper, we present Beaver, a decentralized anonymous However, similar to “traditional” online marketplaces such marketplace that is resistant against Sybil attacks on vendor as eBay, an online anonymous marketplace remains a cen- reputation, while preserving user anonymity. Beaver allows its tralized service. It thus needs to be trusted for availability as participants to enjoy open enrollment, and provides every user customers cannot query item listings or reviews if it is not with the same global view of the reputation of other users through online; it needs to be trusted for correctness, i.e., not inject fake public ledger based consensus. -
CS505: Distributed Systems
Cristina Nita-Rotaru CS505: Distributed Systems Lookup services. Chord. CAN. Pastry. Kademlia. Required Reading } I. Stoica, R. Morris, D. Karger, M. F. Kaashoek, H. Balakrishnan, Chord: A Scalable Peer-to-peer Lookup Service for Internet Applications, SIGCOMM 2001. } A Scalable Content-Addressable Network S.a Ratnasamy, P. Francis, M. Handley, R. Karp, S. Shenker, SIGCOMM 2001 } A. Rowstron and P. Druschel. "Pastry: Scalable, decentralized object location and routing for large-scale peer-to-peer systems". IFIP/ACM International Conference on Distributed Systems Platforms (Middleware), 2001 } Kademlia: A Peer-to-peer Information System Based on the XOR Metric. P. Maymounkov and D. Mazieres, IPTPS '02 2 DHTs 1: Lookup services Peer-to-Peer (P2P) Systems } Applications that take advantage of resources (storage, cycles, content, human presence) available at the edges of the Internet. } Characteristics: } System consists of clients connected through Internet and acting as peers } System is designed to work in the presence of variable connectivity } Nodes at the edges of the network have significant autonomy; no centralized control } Nodes are symmetric in function 4 DHTs Benefits of P2P and Applications } High capacity: all clients provide resources (bandwidth, storage space, and computing power). The capacity of the system increases as more nodes become part of the system. } Increased reliability: achieved by replicating data over multiple peers, and by enabling peers to find the data without relying on a centralized index server. } Applications: -
Practical Anonymous Networking?
gap – practical anonymous networking? Krista Bennett Christian Grothoff S3 lab and CERIAS, Department of Computer Sciences, Purdue University [email protected], [email protected] http://www.gnu.org/software/GNUnet/ Abstract. This paper describes how anonymity is achieved in gnunet, a framework for anonymous distributed and secure networking. The main focus of this work is gap, a simple protocol for anonymous transfer of data which can achieve better anonymity guarantees than many traditional indirection schemes and is additionally more efficient. gap is based on a new perspective on how to achieve anonymity. Based on this new perspective it is possible to relax the requirements stated in traditional indirection schemes, allowing individual nodes to balance anonymity with efficiency according to their specific needs. 1 Introduction In this paper, we present the anonymity aspect of gnunet, a framework for secure peer-to-peer networking. The gnunet framework provides peer discovery, link encryption and message-batching. At present, gnunet’s primary application is anonymous file-sharing. The anonymous file-sharing application uses a content encoding scheme that breaks files into 1k blocks as described in [1]. The 1k blocks are transmitted using gnunet’s anonymity protocol, gap. This paper describes gap and how it attempts to achieve privacy and scalability in an environment with malicious peers and actively participating adversaries. The gnunet core API offers node discovery, authentication and encryption services. All communication between nodes in the network is confidential; no host outside the network can observe the actual contents of the data that flows through the network. Even the type of the data cannot be observed, as all packets are padded to have identical size. -
Zeronet Presentation
ZeroNet Decentralized web platform using Bitcoin cryptography and BitTorrent network. ABOUT ZERONET Why? Current features We believe in open, free, and ◦ Real-time updated sites uncensored network and communication. ◦ Namecoin .bit domain support ◦ No hosting costs ◦ Multi-user sites Sites are served by visitors. ◦ Password less, Bitcoin's BIP32- ◦ Impossible to shut down based authorization It's nowhere because it's ◦ Built-in SQL server with P2P data everywhere. synchronization ◦ No single point of failure ◦ Tor network support Site remains online so long as at least 1 peer serving it. ◦ Works in any browser/OS ◦ Fast and works offline You can access the site even if your internet is unavailable. HOW DOES IT WORK? THE BASICS OF ASYMMETRIC CRYPTOGRAPHY When you create a new site you get two keys: Private key Public key 5JNiiGspzqt8sC8FM54FMr53U9XvLVh8Waz6YYDK69gG6hso9xu 16YsjZK9nweXyy3vNQQPKT8tfjCNjEX9JM ◦ Only you have it ◦ This is your site address ◦ Allows you to sign new content for ◦ Using this anyone can verify if the your site. file is created by the site owner. ◦ No central registry ◦ Every downloaded file is verified, It never leaves your computer. makes it safe from malicious code inserts or any modifications. ◦ Impossible to modify your site without it. MORE INFO ABOUT CRYPTOGRAPHY OF ZERONET ◦ ZeroNet uses the same elliptic curve based encryption as in your Bitcoin wallet. ◦ You can accept payments directly to your site address. ◦ Using the current fastest supercomputer, it would take around 1 billion years to "hack" a private key. WHAT HAPPENS WHEN YOU VISIT A ZERONET SITE? WHAT HAPPENS WHEN YOU VISIT A ZERONET SITE? (1/2) 1 Gathering visitors IP addresses: Please send some IP addresses for site 1EU1tbG9oC1A8jz2ouVwGZyQ5asrNsE4Vr OK, Here are some: 12.34.56.78:13433, 42.42.42.42:13411, .. -
CS 552 Peer 2 Peer Networking
CS 552 Peer 2 Peer Networking R. Martin Credit slides from B. Richardson, I. Stoica, M. Cuenca Peer to Peer • Outline • Overview • Systems: – Gnutella – Freenet – Chord – PlanetP Why Study P2P • Huge fraction of traffic on networks today – >=50%! • Exciting new applications • Next level of resource sharing – Vs. timesharing, client-server, P2P – E.g. Access 10’s-100’s of TB at low cost. P2P usage • CMU network (external to world), 2003 • 47% of all traffic was easily classifiable as P2P • 18% of traffic was HTTP • Other traffic: 35% – Believe ~28% is port- hopping P2P • Other sites have a similar distribution Big Picture • Gnutella – Focus is simple sharing – Using simple flooding • Bit torrent – Designed for high bandwidth • PlanetP – Focus on search and retrieval – Creates global index on each node via controlled, randomized flooding • Cord – Focus on building a distributed hash table (DHT) – Finger tables Other P2P systems • Freenet: – Focus privacy and anonymity – Builds internal routing tables • KaaZa • eDonkey • Napster – Success started the whole craze Key issues for P2P systems • Join/leave – How do nodes join/leave? Who is allowed? • Search and retrieval – How to find content? – How are metadata indexes built, stored, distributed? • Content Distribution – Where is content stored? How is it downloaded and retrieved? Search and Retrieval • Basic strategies: – Flooding the query – Flooding the index – Routing the query • Different tradeoffs depending on application – Robustness, scalability, legal issues Flooding the Query (Gnutella) N3 Lookup(“title”) N1 N2 N4 N5 Key=title N8 N6 Value=mp3 N7 Pros: highly robust. Cons: Huge network traffic Flooding the Index (PlanetP) Key1=title1 N3 N1 Key2=title2 N2 N4 N5 Lookup(“title4”) Key1=title3 N8 N6 Key2=title4 N7 Pros: Robust. -
Title: P2P Networks for Content Sharing
Title: P2P Networks for Content Sharing Authors: Choon Hoong Ding, Sarana Nutanong, and Rajkumar Buyya Grid Computing and Distributed Systems Laboratory, Department of Computer Science and Software Engineering, The University of Melbourne, Australia (chd, sarana, raj)@cs.mu.oz.au ABSTRACT Peer-to-peer (P2P) technologies have been widely used for content sharing, popularly called “file-swapping” networks. This chapter gives a broad overview of content sharing P2P technologies. It starts with the fundamental concept of P2P computing followed by the analysis of network topologies used in peer-to-peer systems. Next, three milestone peer-to-peer technologies: Napster, Gnutella, and Fasttrack are explored in details, and they are finally concluded with the comparison table in the last section. 1. INTRODUCTION Peer-to-peer (P2P) content sharing has been an astonishingly successful P2P application on the Internet. P2P has gained tremendous public attention from Napster, the system supporting music sharing on the Web. It is a new emerging, interesting research technology and a promising product base. Intel P2P working group gave the definition of P2P as "The sharing of computer resources and services by direct exchange between systems". This thus gives P2P systems two main key characteristics: • Scalability: there is no algorithmic, or technical limitation of the size of the system, e.g. the complexity of the system should be somewhat constant regardless of number of nodes in the system. • Reliability: The malfunction on any given node will not effect the whole system (or maybe even any other nodes). File sharing network like Gnutella is a good example of scalability and reliability. -
Escaping the Ossification Trap with Gnunet
Escaping the Ossification Trap with GNUnet Christian Grothoff BFH & The GNU Project 25.1.2018 \We shape our tools, and thereafter our tools shape us". {John Culkin What can be done? I Democracies are slow ) Effective regulation of mega-corporations exists only under dictatorships Dictatorship or Corpocracy? Regulation? I Charles Stross (@34c4) warns: Companies are AIs that develop faster than the law I Julia Reda (@IGF) warns: Regulation of platforms paradoxically can give them more power Regulation? I Charles Stross (@34c4) warns: Companies are AIs that develop faster than the law I Julia Reda (@IGF) warns: Regulation of platforms paradoxically can give them more power I Democracies are slow ) Effective regulation of mega-corporations exists only under dictatorships Dictatorship or Corpocracy? Better Technology! Data protection! Decentralization! Self-Organization! Technological impact assessment!1 1Difficult, but better than design-by-buzzword! Technological impact assessment case-study: Name systems DNS/DNSSEC DNS Server Root Zone a.root-servers.net. www.example.com? a.gtld-servers.net.test E2D3C9.... DNSSEC Trust Anchor NS . S4LXnQiBS... 49AAC1... DS RRSIG www.example.com? Recursive DNS Server Stub www.example.com? Name .com Resolver Server NS a.gtld-servers.net.test a.gtld-servers.net. A 93.184.216.119 DS 3490A6.... RRSIG example.com. K0rp9n... RRSIG com. U/ZW6P3c... AD www.example.com? RRSIG A 93.184.216.119 example.com. K0rp9n... DNS Server example.com a.iana-servers.net. RAINS Authority Server Root Zone 44 ) com ZK ; :registry www.example.com? -
1 Explain How Freenet Enables Individuals to Publish Anonymous Web Pages That Are Extremely Difficult to Censor. Does This Mean
Explain how FreeNet enables individuals to publish anonymous web pages that are extremely difficult to censor. Does this mean that the battle against state censorship in oppressive regimes has been won? Abstract Anonymity is a necessity for free speech, without it democracy cannot exist. Ensuring that anonymity has been hard to do online, however Freenet is a novel attempt to ensure anonymity. By encrypting and fragmenting documents which are stored on multiple nodes, and ensuring that nodes can only talk to a small subset, rather than a whole network, an individual’s anonymity becomes stronger. While Freenet does not make it impossible to trace what someone has downloaded, it does make it much harder. Freenet is a big step towards enabling people living in countries with oppressive governments to voice their views. Why is Anonymity important? The first amendment in the United States constitution is arguably one of the most important, and most controversial articles of law. It states that individuals have the right to free speech, free from persecution. Democracy is based on individuals electing representatives, based on their performance and what they say they will do. If freedom of speech is denied, then it is not possible for anyone to critique the government, and evaluate whether they are truly carrying out their responsibilities, or whether another party would be more appropriate. Indeed, without free speech, it is 1 impossible for other parties to exist, as their views will inevitably contradict that of the current government in power. Free speech can be ensured by anonymity. If an oppressive government does not know who is criticizing it, then it cannot punish the individual.