Anonymous P2P

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An anonymous P2P computer network is a particular type of peer-to-peer network in which the users and their nodes are pseudonymous by default. The primary difference between regular and anonymous networks is in the routing method of their respective network architectures. These networks allow for unfettered free flow of information, legal or otherwise.

The P2P community's interest in anonymous P2P has increased rapidly in recent years for many reasons, including distrust of government (especially in undemocratic regimes), and digital imprimatur. Such a network may also appeal to those wishing to share copyrighted files illegally - organizations such as the Recording Industry Association of America have successfully tracked and threatened to sue users on non-anonymous P2P networks.

1 Anonymous P2P as a misnomer
2 Views on the desirability of anonymous P2P
3 Consequences of P2P anonymity
4 Technical drawbacks of current anonymous P2P networks
5 Pseudonymous P2P clients
6 Private P2P clients
7 Friend-to-friend clients
8 References
9 See also
- 9.1 Hypothetical or defunct networks
10 External links

[edit] Anonymous P2P as a misnomer

The term 'anonymous P2P' is somewhat of a misnomer. This is because by design, a network node must be pseudonymous since it must have an "address" at which it can be reached by other peer nodes in order to exchange data. However, usually this address, especially on anonymous networks, does not contain any directly identifiable information. Thus a user is highly, but not completely, anonymous. (In friend-to-friend networks, only your friends can know that your address is used to exchange files.)

When receiving data on any network it must come from somewhere and data must have been requested by someone. The anonymity comes from the idea that no one knows who requested the information as it is difficult - if not impossible - to determine if a user requested the data for himself or simply requested the data on behalf of another user. The end result is that everyone on an anonymous network acts as a universal sender and universal receiver to maintain anonymity.

If people are only universal receivers and do not send, then one would know that the information they were requesting was for themselves only, removing any plausible deniability that they were the recipients (and consumers) of the information. Thus, in order to remain anonymous, one must ferry information for others on the network.

[edit] Views on the desirability of anonymous P2P

Such technology is desirable and in some cases necessary to ensure freedom of speech and the free flow of information. The claim is 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 in many democracies.

Anonymous P2P also has value in normal daily communication. When communication is anonymous, the decision to reveal the identity 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 party to be forced to reveal their identity. As a matter of personal freedom, many people do not want processes in place by default which supply unnecessary data. Such data, could also be complied into histories of their activities, and which in their opinion, should be inherently controlled by the caller, not the called.

For example the current phone system transmits caller ID information by default to the other party. If one is calling to make an inquiry about a product or a time of a movie, the person called has a record of the phone number which called and therefore the name, address and the potential for more information about the person. If one were to walk into a store or up to a person on the street and make a similar inquiry all this personal information would not be involved. Anonymous P2P simply allows for a currently existing activity in “meatspace” to now occur over a communications network.

Some friend-to-friend networks allow you to control what kind of files your friends exchange with your node, in order to stop them from exchanging files that you disapprove of.

A common ideal for anonymous peer to peer networks is to make it impossible to hinder the spread of information. This is typically achieved through encryption, making all kinds of information indistinguishable from each other.

[edit] Consequences of P2P anonymity

While anonymous P2P systems may support the protection of unpopular speech, they may also protect illegal activities not protected under free speech, such as fraud, libel, the exchange of illegal pornography, the unauthorized copying of music and films, the planning of criminal activities, distribution of untraceable spam, or denial-of-service attacks. Critics of such systems hold that the advantages offered by such systems do not outweigh these disadvantages, and that other communication channels are already sufficient for unpopular speech.

Pornography trading is one public reason against anonymous P2P networks, and some believe that the networks aid terrorism. There are several responses to these criticisms. The first is that all information is neutral, and that it is the people acting upon the information that can be good or evil. The second is that perceptions of good and evil change (See moral panic): If anonymous peer-to-peer networks had been around in the 1950s or 1960s, they might have been targeted for carrying information about civil rights or anarchism.

Other issues include:

Anonymous spam, and DDoS attacks can be performed.
It is difficult or impossible to uphold laws that can be broken through P2P networks. This could lead to the breakdown of intellectual property (though see digital rights management and copyright social conflict).
With anonymous money, it becomes possible to arrange anonymous markets where one can buy and sell just about anything anonymously. Assassination markets would be a potential result of this, for instance. Also note that any transfer of physical goods between two parties could compromise anonymity. Anonymous money could be used to avoid tax collection. That could lead to a movement towards anarcho-capitalism. It is highly unlikely that all transactions could be done anonymously, however, and a government could still rely on property taxes.
It is easy to publish any information you want without the possibility of having your physical identity revealed. This could be used to openly publish information that governments forbid, like warez, software violating software patents, and child pornography. On the other hand, controversial information which a party wants to keep hidden, such as details about corruption issues, can be anonymously published.

[edit] Technical drawbacks of current anonymous P2P networks

There are a variety of drawbacks in the current design of many anonymous P2P applications and networks. One of the major ones is that it is difficult or impossible to hide the fact you are running such an application, meaning that a government could simply outlaw its use to prevent the free flow of information. In countries where strong encryption is forbidden, governments have easy leverage to forbid anonymous P2P.

These drawbacks do not apply to some Friend-to-friend networks, and to anonymous P2P used on a wireless mesh network: 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. 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, or require every wireless device to be registered under the owner's name. Protocols for wireless mesh networks are OLSR and the follow up protocol B.A.T.M.A.N., which is designed for decentralized auto-ip assignment.

[edit] Pseudonymous P2P clients

ANts P2P is a P2P file sharing system which anonymizes and encrypts traffic, and supports HTTP publishing
Azureus, a BitTorrent client with the option of using I2P or Tor (open source, written in Java)
Entropy - a Freenet alternative
Freenet - a censorship-resistant distributed file system for anonymous publishing (open source, written in Java)
GNUnet - an anonymizing file sharing application
I2P - an anonymizing network layer upon which applications can be built (open source, written in Java)
i2phex - a Gnutella client which communicates anonymously through I2P
Marabunta - an anonymous distributed P2P network which uses only UDP
MUTE - an anonymizing file sharing client. MFC Mute, Kommute and Napshare are alternative clients
Nodezilla - an anonymizing, closed source network layer upon which applications can be built (written in C++ and Java)
Rodi - a file sharing client which allows for a low degree of anonymity
RShare - a file sharing system which anonymizes and encrypts the traffic
Share - the successor to Winny; the biggest file sharing network in Japan
Tor - While Tor is not a P2P client itself, it provides a method for other P2P programs to become anonymous. It is also one of the larger research projects for anonymous networks.
Winny - was very popular in Japan (freeware, written in C++ for Windows)

[edit] Private P2P clients

Main article: Private P2P

Private P2P networks are P2P networks that only allow some mutually trusted computers to share files. The functionality is similar to a group of private FTP servers, but the user interface is the same as most of the other P2P programs.

Allpeers - Search in buddies
Cspace - encrypted and serverless instant messenger
GigaTribe - a free P2P file sharing system which anonymizes and encrypts exchanged data; no limit to sizes of folders or files that are exchanged.
PowerFolder - Private and Secure Filesharing with friends and colleges over the internet or LAN.

[edit] Friend-to-friend clients

Main article: Friend-to-friend

A Friend-to-friend network is not just a group of private FTP servers. Your F2F node can automatically forward a file (or a request for a file) anonymously between two of your friends. When forwarding a file or a request between two friends, your node doesn't tell any of them who is the other and what is the other address. Then these friends' nodes can in turn forward anonymously this same file (or request) to several of their own friends and so on. Thus F2F networks can grow in size without compromising the users' anonymity.

Freenet from 0.7 up
GNUnet with its "F2F topology" option
Turtle F2F
WASTE

[edit] References

↑ Watters, P.A., Martin, F. & Stripf, S. (2005). Visual steganalysis of LSB-encoded natural images. 3rd IEEE International Conference on Information Technology and Applications, Sydney, Australia.