An anonymous P2P communication system is a

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...

distributed application A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer sci ...

in which the nodes, which are used to share resources, or participants are

anonymous Anonymous may refer to: * Anonymity, the state of an individual's identity, or personally identifiable information, being publicly unknown ** Anonymous work, a work of art or literature that has an unnamed or unknown creator or author * Anonym ...

or pseudonymous. Anonymity of participants is usually achieved by special routing overlay networks that hide the physical location of each node from other participants. Interest in anonymous P2P systems has increased in recent years for many reasons, ranging from the desire to share files without revealing one's network identity and risking

litigation - A lawsuit is a proceeding by a party or parties against another in the civil court of law. The archaic term "suit in law" is found in only a small number of laws still in effect today. The term "lawsuit" is used in reference to a civil actio ...

Electronic Frontier Foundation (2005)
RIAA v. The People: Five Years Later
. Retrieved March 5, 2008. to distrust in governments, concerns over mass surveillance and

data retention Data retention defines the policies of persistent data and records management for meeting legal and business data archival requirements. Although sometimes interchangeable, it is not to be confused with the Data Protection Act 1998. The different ...

, and

lawsuit - A lawsuit is a proceeding by a party or parties against another in the civil court of law. The archaic term "suit in law" is found in only a small number of laws still in effect today. The term "lawsuit" is used in reference to a civil actio ...

s against

blog A blog (a truncation of "weblog") is a discussion or informational website published on the World Wide Web consisting of discrete, often informal diary-style text entries (posts). Posts are typically displayed in reverse chronological order ...

gers.

Motivation for anonymity

There are many reasons to use anonymous P2P technology; most of them are generic to all forms of online anonymity. P2P users who desire anonymity usually do so as they do not wish to be identified as a publisher (sender), or reader (receiver), of information. Common reasons include: *

Censorship Censorship is the suppression of speech, public communication, or other information. This may be done on the basis that such material is considered objectionable, harmful, sensitive, or "inconvenient". Censorship can be conducted by governments ...

at the local, organizational, or national level * Personal privacy preferences such as preventing

tracking Tracking may refer to: Science and technology Computing * Tracking, in computer graphics, in match moving (insertion of graphics into footage) * Tracking, composing music with music tracker software * Eye tracking, measuring the position of ...

or data mining activities * The material or its distribution is considered illegal or incriminating by possible eavesdroppers * Material is legal but socially deplored, embarrassing or problematic in the individual's

social world Social reality is distinct from biological reality or individual cognitive reality, representing as it does a phenomenological level created through social interaction and thereby transcending individual motives and actions. As a product of human ...

* Fear of retribution (against

whistleblower A whistleblower (also written as whistle-blower or whistle blower) is a person, often an employee, who reveals information about activity within a private or public organization that is deemed illegal, immoral, illicit, unsafe or fraudulent. Whi ...

s, unofficial leaks, and

activist Activism (or Advocacy) consists of efforts to promote, impede, direct or intervene in social, political, economic or environmental reform with the desire to make changes in society toward a perceived greater good. Forms of activism range fr ...

s who do not believe in restrictions on information nor

knowledge Knowledge can be defined as awareness of facts or as practical skills, and may also refer to familiarity with objects or situations. Knowledge of facts, also called propositional knowledge, is often defined as true belief that is disti ...

) A particularly open view on legal and illegal content is given i
The Philosophy Behind Freenet
Governments are also interested in anonymous P2P technology. The

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

funded the original

onion routing Onion routing is a technique for anonymous communication over a computer network. In an onion network, messages are encapsulated in layers of encryption, analogous to layers of an onion. The encrypted data is transmitted through a series of net ...

research that led to the development of the Tor network, which was later funded by the

Electronic Frontier Foundation The Electronic Frontier Foundation (EFF) is an international non-profit digital rights group based in San Francisco, California. The foundation was formed on 10 July 1990 by John Gilmore, John Perry Barlow and Mitch Kapor to promote Internet ...

and is now developed by the non-profit organization The Tor Project, Inc.

Arguments for and against anonymous P2P communication

General

While anonymous P2P systems may support the protection of unpopular speech, they may also protect illegal activities, such as

fraud In law, fraud is intentional deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud can violate civil law (e.g., a fraud victim may sue the fraud perpetrator to avoid the fraud or recover monetary compen ...

libel Defamation is the act of communicating to a third party false statements about a person, place or thing that results in damage to its reputation. It can be spoken (slander) or written (libel). It constitutes a tort or a crime. The legal defi ...

, the exchange of illegal

pornography Pornography (often shortened to porn or porno) is the portrayal of sexual subject matter for the exclusive purpose of sexual arousal. Primarily intended for adults,

, the unauthorized copying of

copyright A copyright is a type of intellectual property that gives its owner the exclusive right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, education ...

ed works, or the planning of criminal activities. Critics of anonymous P2P systems hold that these disadvantages outweigh the advantages offered by such systems, and that other communication channels are already sufficient for unpopular speech. Proponents of anonymous P2P systems believe that all restrictions on free speech serve authoritarian interests, information itself is ethically neutral, and that it is the people acting upon the information that can be good or evil. Perceptions of good and evil can also change (see

moral panic A moral panic is a widespread feeling of fear, often an irrational one, that some evil person or thing threatens the values, interests, or well-being of a community or society. It is "the process of arousing social concern over an issue", usua ...

); for example, if anonymous peer-to-peer networks had existed in the 1950s or 1960s, they might have been targeted for carrying information about

civil rights Civil and political rights are a class of rights that protect individuals' freedom from infringement by governments, social organizations, and private individuals. They ensure one's entitlement to participate in the civil and political life ...

or anarchism. Easily accessible anonymous P2P networks are seen by some as a democratization of

encryption In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can dec ...

technology, giving the general populace access to secure communications channels already used by governments. Supporters of this view, such as

Phil Zimmermann Philip R. Zimmermann (born 1954) is an American computer scientist and cryptographer. He is the creator of Pretty Good Privacy (PGP), the most widely used email encryption software in the world. He is also known for his work in VoIP encryptio ...

, argue that anti-surveillance technologies help to equalize power between governments and their people,Russell D. Hoffmann (1996)
Interview with author of PGP (Pretty Good Privacy)
. Transcript of a radio interview, retrieved 2008-01-21. which is the actual reason for banning them. John Pilger opines that monitoring of the populace helps to contain threats to the "consensual view of established authority"John Pilger (2002)
Impartiality of British Journalism
ZNet article, retrieved 2008-02-11. or threats to the continuity of power structures and privilege.

Freedom of speech

Some claim that true freedom of speech, especially on controversial subjects, is difficult or impossible unless individuals can speak anonymously. If anonymity is not possible, one could be subjected to threats or reprisals for voicing an unpopular view. This is one reason why voting is done by secret

ballot A ballot is a device used to cast votes in an election and may be found as a piece of paper or a small ball used in secret voting. It was originally a small ball (see blackballing) used to record decisions made by voters in Italy around the 16 ...

in many democracies. Controversial information which a party wants to keep hidden, such as details about corruption issues, is often published or leaked anonymously.

Anonymous blogging

Anonymous blogging is one widespread use of anonymous networks. While anonymous blogging is possible on the non-anonymous internet to some degree too, a provider hosting the blog in question might be forced to disclose the blogger's

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...

(as when Google revealed an anonymous blogger's identity). Anonymous networks provide a better degree of anonymity. Flogs (anonymous blogs) in Freenet, Syndie and other blogging tools in I2P and Osiris sps are some examples of anonymous blogging technologies. One argument for anonymous blogging is a delicate nature of work situation. Sometimes a blogger writing under their real name faces a choice between either staying silent or causing a harm to themselves, their colleagues or the company they work for. Another reason is risk of lawsuits. Some bloggers have faced multimillion-dollar lawsuits (although they were later dropped completely); anonymous blogging provides protection against such risks.

Censorship via Internet domain names

On the non-anonymous Internet, a

domain name A domain name is a string that identifies a realm of administrative autonomy, authority or control within the Internet. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. ...

like " example.com" is a key to accessing information. The censorship of the Wikileaks website shows that domain names are extremely vulnerable to censorship. Some domain registrars have suspended customers' domain names even in the absence of a court order. For the affected customer, blocking of a domain name is a far bigger problem than a registrar refusing to provide a service; typically, the registrar keeps full control of the domain names in question. In the case of a European travel agency, more than 80 .com websites were shut down without any court process and held by the registrar since then. The travel agency had to rebuild the sites under the .net

top-level domain A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the root zone of the name space. For all domains in ...

instead. On the other hand, anonymous networks do not rely on

domain name registrar A domain name registrar is a company that manages the reservation of Internet domain names. A domain name registrar must be accredited by a generic top-level domain (gTLD) registry or a country code top-level domain (ccTLD) registry. A registr ...

s. For example, Freenet, I2P and Tor hidden services implement censorship-resistant URLs based on

public-key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic a ...

: only a person having the correct private key can update the URL or take it down.

Control over online tracking

Anonymous P2P also has value in normal daily communication. When communication is anonymous, the decision to reveal the identities of the communicating parties is left up to the parties involved and is not available to a third party. Often there is no need or desire by the communicating parties to reveal their identities. As a matter of personal freedom, many people do not want processes in place by default which supply unnecessary data. In some cases, such data could be compiled into histories of their activities. For example, most current phone systems transmit caller ID information by default to the called party (although this can be disabled either for a single call or for all calls). If a person calls to make an inquiry about a product or the time of a movie, the party called has a record of the calling phone number, and may be able to obtain the name, address and other information about the caller. This information is not available about someone who walks into a store and makes a similar inquiry.

Effects of surveillance on lawful activity

Online surveillance, such as recording and retaining details of web and e-mail traffic, may have effects on lawful activities.Dawinder S. Sidhu (2007)
The chilling effect of government surveillance programs on the use of the internet by Muslim-Americans
. University of Maryland Law Journal of Race, Religion, Gender and Class. People may be deterred from accessing or communicating legal information because they know of possible surveillance and believe that such communication may be seen as suspicious. According to law professor Daniel J. Solove, such effects "harm society because, among other things, they reduce the range of viewpoints being expressed and the degree of freedom with which to engage in political activity."Daniel J. Solove (2006)
"I've got nothing to hide" and other misunderstandings of privacy
. San Diego Law Review, Vol. 44.

Access to censored and copyrighted material

Most countries ban or censor the publication of certain

books A book is a medium for recording information in the form of writing or images, typically composed of many pages (made of papyrus, parchment, vellum, or paper) bound together and protected by a cover. The technical term for this physica ...

and

movies A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...

, and certain types of content. Other material is legal to possess but not to distribute; for example, copyright and

software patent A software patent is a patent on a piece of software, such as a computer program, Library (computing), libraries, user interface, or algorithm. Background A patent is a set of exclusionary rights granted by a State (polity), state to a patent h ...

laws may forbid its distribution. These laws are difficult or impossible to enforce in anonymous P2P networks.

Anonymous online money

With

anonymous money Anonymous may refer to: * Anonymity, the state of an individual's identity, or personally identifiable information, being publicly unknown ** Anonymous work, a work of art or literature that has an unnamed or unknown creator or author * Anony ...

, it becomes possible to arrange anonymous markets where one can buy and sell just about anything anonymously. Anonymous money could be used to avoid tax collection. However, any transfer of physical goods between two parties could compromise anonymity.Rob Thomas, Jerry Martin (2006)
The underground economy: priceless
. Retrieved 2008-01-20. Proponents argue that conventional

cash In economics, cash is money in the physical form of currency, such as banknotes and coins. In bookkeeping and financial accounting, cash is current assets comprising currency or currency equivalents that can be accessed immediately or near-immed ...

provides a similar kind of anonymity, and that existing laws are adequate to combat crimes like

tax evasion Tax evasion is an illegal attempt to defeat the imposition of taxes by individuals, corporations, trusts, and others. Tax evasion often entails the deliberate misrepresentation of the taxpayer's affairs to the tax authorities to reduce the tax ...

that might result from the use of anonymous cash, whether online or offline.

Functioning of anonymous P2P

Anonymity and pseudonymity

Some of the networks commonly referred to as "anonymous P2P" are truly anonymous, in the sense that network nodes carry no identifiers. Others are actually pseudonymous: instead of being identified by their IP addresses, nodes are identified by pseudonyms such as cryptographic keys. For example, each node in the MUTE network has an overlay address that is derived from its public key. This overlay address functions as a pseudonym for the node, allowing messages to be addressed to it. In Freenet, on the other hand, messages are routed using keys that identify specific pieces of data rather than specific nodes; the nodes themselves are anonymous. The term ''anonymous'' is used to describe both kinds of network because it is difficult—if not impossible—to determine whether a node that sends a message originated the message or is simply forwarding it on behalf of another node. Every node in an anonymous P2P network acts as a universal sender and universal receiver to maintain anonymity. If a node was only a receiver and did not send, then neighbouring nodes would know that the information it was requesting was for itself only, removing any

plausible deniability Plausible deniability is the ability of people, typically senior officials in a formal or informal chain of command, to deny knowledge of or responsibility for any damnable actions committed by members of their organizational hierarchy. They may ...

that it was the recipient (and consumer) of the information. Thus, in order to remain anonymous, nodes must ferry information for others on the network.

Spam and DoS attacks in anonymous networks

Originally, anonymous networks were operated by small and friendly communities of developers. As interest in anonymous P2P increased and the user base grew, malicious users inevitably appeared and tried different attacks. This is similar to the Internet, where widespread use has been followed by waves of spam and distributed DoS (

Denial of Service In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host conn ...

) attacks. Such attacks may require different solutions in anonymous networks. For example, blacklisting of originator network addresses does not work because anonymous networks conceal this information. These networks are more vulnerable to DoS attacks as well due to the smaller bandwidth, as has been shown in examples on the Tor network. A conspiracy to attack an anonymous network could be considered criminal computer hacking, though the nature of the network makes this impossible to prosecute without compromising the anonymity of data in the network.

Opennet and darknet network types

Like conventional P2P networks, anonymous P2P networks can implement either opennet or darknet (often named friend-to-friend) network type. This describes how a node on the network selects peer nodes: * In opennet network, peer nodes are discovered automatically. There is no configuration required but little control available over which nodes become peers. * In a darknet network, users manually establish connections with nodes run by people they know. Darknet typically needs more effort to set up but a node only has trusted nodes as peers. Some networks like Freenet support both network types simultaneously (a node can have some manually added darknet peer nodes and some automatically selected opennet peers) . In a friend-to-friend (or F2F) network, users only make direct connections with people they know. Many F2F networks support indirect anonymous or pseudonymous communication between users who do not know or trust one another. For example, a node in a friend-to-friend overlay can automatically forward a file (or a request for a file) anonymously between two "friends", without telling either of them the other's name or IP address. These "friends" can in turn forward the same file (or request) to their own "friends", and so on. Users in a friend-to-friend network cannot find out who else is participating beyond their own circle of friends, so F2F networks can grow in size without compromising their users' anonymity. Some friend-to-friend networks allow the user to control what kind of files can be exchanged with "friends" within the node, in order to stop them from exchanging files that user disapproves of. Advantages and disadvantages of opennet compared to darknet are disputed, see friend-to-friend article for summary.

List of anonymous P2P networks and clients

Public P2P clients

* Classified-ads - an

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

DHT-based decentralized messaging and voice app. Allows users to not expose any personal details but does not hide network addresses of nodes. * DarkMX - a file-sharing client modeled on WinMX/ Tixati with a built-in implementation of Tor. * DigitalNote XDN - an open-source anonymous

decentralized Decentralization or decentralisation is the process by which the activities of an organization, particularly those regarding planning and decision making, are distributed or delegated away from a central, authoritative location or group. Conce ...

encrypted messaging system based on blockchain technology *

Freenet Freenet is a peer-to-peer platform for censorship-resistant, anonymous communication. It uses a decentralized distributed data store to keep and deliver information, and has a suite of free software for publishing and communicating on the Web ...

- a censorship-resistant

distributed file system A clustered file system is a file system which is shared by being simultaneously mounted on multiple servers. There are several approaches to clustering, most of which do not employ a clustered file system (only direct attached storage for ...

for anonymous publishing (open source, written in Java) * GNUnet - a P2P framework, includes anonymous file sharing as its primary application (

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing devi ...

, written in C, alpha status) * MuWire - a filesharing software, with chat rooms. Even if running inside the I2P network, it is not called a 'I2P client' because it has a I2P router embedded, so this makes it a standalone software. * Perfect Dark - a Japanese file-sharing client based on a distributed data store. One can see the IP address of connected nodes, but not what they are up or downloading. Amoeba is a similar client/network. * Tribler - an

BitTorrent

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuabl ...

. It can be set to have neighboring nodes act as proxies between one's client and the torrent swarm. The proxy can see what file is being uploaded, but most nodes in the swarm only see the exit node. *

ZeroNet ZeroNet is a decentralized web-like network of peer-to-peer users, created by Tamas Kocsis in 2015, programming for the network was based in Budapest, Hungary; is built in Python; and is fully open source. Instead of having an IP address, ...

- a decentralized

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consists ...

-like network of peer-to-peer users. Allows tunneling of HTTP-traffic through Tor.

I2P clients

* I2P - a fully

overlay network for strong anonymity and

end-to-end encryption End-to-end encryption (E2EE) is a system of communication where only the communicating users can read the messages. In principle, it prevents potential eavesdroppers – including telecom providers, Internet providers, malicious actors, and eve ...

, with many applications (P2P, browsing, distributed anonymous e-mail,

instant messaging Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and trigge ...

, IRC, ...) running on top of it (free/open source, platform-independent) * I2P-Bote an anonymous, secure (end-to-end encrypted), serverless mail application with remailer functionality for the I2P network * I2P-Messenger an anonymous, secure (end-to-end encrypted), serverless instant messenger for the I2P network *

I2PSnark I, or i, is the ninth letter and the third vowel letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''i'' (pronounced ), plural ...

- an anonymous BitTorrent client for the I2P network * I2Phex - a

Gnutella Gnutella is a peer-to-peer network protocol. Founded in 2000, it was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model. In June 2005, Gnutella's population was 1.81 million computer ...

client which communicates anonymously through I2P * iMule - an aMule port running under I2P network * Robert (P2P Software) - another anonymous BitTorrent client for the I2P network * I2P-Tahoe-LAFS - a censorship-resistant

for anonymous publishing and file sharing (open source, written in Python, pre-alpha status) * Vuze (formerly Azureus) - a

BitTorrent client The following is a general comparison of BitTorrent clients, which are computer programs designed for peer-to-peer file sharing using the BitTorrent protocol. The BitTorrent protocol coordinates segmented file transfer among peers connected ...

with the option of using I2P or Tor (initially open source, written in Java) * BiglyBT - a successor to Vuze. A

where downloads can be routed through I2P, and searches carried out through Tor (open source, written in Java)

Defunct (Public P2P clients) or no longer developed

Bitblinder Bitblinder was an open source software program that allows users to share bandwidth and IP addresses in order to anonymously download torrents and browse the internet. It was first released in June 2009. under an MIT open-source license. It was ...

(2009-2010) - file sharing * Bitmessage - an anonymous

messaging system serving as a secure replacement for email * Cashmere (2005) - resilient anonymous routing * Entropy (2003-2005) - Freenet compatible *

EarthStation 5 Earth Station 5 (ES5) was a peer-to-peer network active between 2003 and 2005, operated by a company of the same name. The user client application also shared this name. Earth Station 5 was notable for its strong, if overstated, emphasis on user ...

(2003-2005) - anonymity controverted * Herbivore (2003-2005) - file sharing and messaging. Used the Dining cryptographers problem. * Marabunta (2005-2006) - distributed chat * MUTE (2003-2009) - file sharing * NeoLoader - a filesharing software compatible with bittorrent and

edonkey2000 eDonkey2000 (nicknamed "ed2k") was a peer-to-peer file sharing application developed by US company MetaMachine ( Jed McCaleb and Sam Yagan), using the Multisource File Transfer Protocol. This client supports both the eDonkey2000 network and t ...

. Anonymous when used with the "NeoShare" feature (that use the proprietary "NeoKad" network) * Netsukuku - a peer-to-peer routing system aiming to build a free and independent Internet *

Nodezilla Nodezilla is a peer-to-peer network software written in C++ (core, aka Network Agent) and Java (GUI), and the GUI part is released under the GNU General Public License. It attempts to provide anonymity. Features Technically, Nodezilla is a ...

(2004-2010) - an anonymizing, closed source network layer upon which applications can be built *

Osiris Osiris (, from Egyptian ''wsjr'', cop, ⲟⲩⲥⲓⲣⲉ , ; Phoenician: 𐤀𐤎𐤓, romanized: ʾsr) is the god of fertility, agriculture, the afterlife, the dead, resurrection, life, and vegetation in ancient Egyptian religion. He ...

(Serverless Portal System) - an anonymous and distributed

web portal A web portal is a specially designed website that brings information from diverse sources, like emails, online forums and search engines, together in a uniform way. Usually, each information source gets its dedicated area on the page for displa ...

s creator. *

OFF System The Owner-Free File System (''OFF System'', or ''OFFS'' for short) is a peer-to-peer distributed file system in which all shared files are represented by randomized multi-used data blocks. Instead of anonymizing the network, the data blocks are ...

(2006-2010) - a P2P

through which all shared files are represented by randomized data blocks * RShare (2006-2007) - file sharing * Share - a Japanese filesharing client modeled on

Winny Winny (also known as WinNY) is a Japanese peer-to-peer (P2P) file-sharing program developed by Isamu Kaneko, a research assistant at the University of Tokyo in 2002. Like Freenet, a user must add an encrypted node list in order to connect to oth ...

* Syndie - a content (mainly forums) syndication program that operates over numerous anonymous and non-anonymous networks (open source, written in Java) * StealthNet (2007-2011) - the successor to RShare *

- a Japanese filesharing program modeled on

which relies on a mixnet and distributed datastore to provide anonymity

Private P2P clients

Private P2P networks are P2P networks that only allow some mutually trusted computers to share files. This can be achieved by using a central server or hub to authenticate clients, in which case the functionality is similar to a private FTP server, but with files transferred directly between the clients. Alternatively, users can exchange passwords or keys with their friends to form a decentralized network. Examples include: * Syncthing - is a

free Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procur ...

open-source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

file synchronization application. It can sync files between devices. Data security and data safety are built into the design of the software. * Resilio Sync - a proprietary alternative to Syncthing

Private F2F (friend-to-friend) clients

Friend-to-friend networks are P2P networks that allows users only to make direct connections with people they know. Passwords or digital signatures can be used for authentication. Examples include : * Filetopia - not anonymous but encrypted friend-to-friend. File sharing, chat, internal mail service *

OneSwarm OneSwarm is a file sharing software that uses the BitTorrent protocol to share files anonymously between users. One application of the software is the ability to access the Dark Web The dark web is the World Wide Web content that exists on ''d ...

- a backwards compatible BitTorrent client with privacy-preserving sharing options, aims to create a large F2F network. * Retroshare - filesharing, serverless email, instant messaging, VoIP, chatrooms, and decentralized forums.

Hypothetical or defunct networks

Hypothetical

The following networks only exist as design or are in development *

anoNet anoNet is a decentralized friend-to-friend network built using VPNs and software BGP routers. anoNet works by making it difficult to learn the identities of others on the network allowing them to anonymously host IPv4 and IPv6 services. Moti ...

- extensible IP anonymizer with steganography support (in development) * Crowds - Reiter and Rubin's system for "blending into a crowd" has a known attack * P2PRIV - Peer-to-Peer diRect and anonymous dIstribution oVerlay - anonymity via virtual links parallelization - currently in development and has significant, unsolved problems in a real world environment * Phantom Anonymity Protocol - a fully decentralized high-throughput anonymization network (no longer in development) * Race ( Resilient Anonymous Communication for Everyone) - A project by DARPA to build an anonymous, attack-resilient mobile communication system that can reside completely within a network environment, capable of avoiding large-scale compromise by preventing compromised information from being useful for identifying any of the system nodes because all such information is encrypted on the nodes at all times, even during computation; and preventing communications compromise by virtue of obfuscating communication protocols.

Defunct or dormant

- a decentralised P2P anonymity software program which included Tor but with increased speed. Website is down and clients are no longer functional. * Invisible IRC Project - anonymous IRC, inspired by

, which later became I2P (Invisible Internet Project). * Mnet (formerly MojoNation) - a

Anonymous P2P in a wireless mesh network

It is possible to implement anonymous P2P on a

wireless mesh network A wireless mesh network (WMN) is a Telecommunications network, communications network made up of radio Node (networking), nodes organized in a Mesh networking, mesh Network topology, topology. It can also be a form of wireless ad hoc network.Chai ...

; unlike fixed Internet connections, users don't need to sign up with an ISP to participate in such a network, and are only identifiable through their hardware. Protocols for

s are Optimized Link State Routing Protocol (OLSR) and the follow-up protocol

B.A.T.M.A.N. The Better Approach to Mobile Ad-hoc Networking (B.A.T.M.A.N.) is a routing protocol for Multi-hop routing, multi-hop mobile ad hoc networks which is under development by the German "Freifunk" community and intended to replace the Optimized Link ...

, which is designed for decentralized auto-IP assignment. See also Netsukuku. Even if a government were to outlaw the use of wireless P2P software, it would be difficult to enforce such a ban without a considerable infringement of personal freedoms. Alternatively, the government could outlaw the purchase of the wireless hardware itself.

about various anonymous P2P applications
A survey of anonymous peer-to-peer file-sharing
(2005)
Anonymous, Decentralized and Uncensored File-Sharing is Booming
by

TorrentFreak __NOTOC__ TorrentFreak (TF) is a blog dedicated to reporting the latest news and trends on the BitTorrent protocol and file sharing, as well as on copyright infringement and digital rights. The website was started in November 2005 by a Dutch ...

(2011) Anonymous file sharing networks Anonymity networks Internet privacy software Crypto-anarchism Peer-to-peer