Pseudonymous remailer
Encyclopedia
A pseudonymous remailer or nym server, as opposed to an anonymous remailer
, is an Internet
software program designed to allow people to write pseudonym
ous messages on Usenet
newsgroups and send pseudonymous email
. Unlike purely anonymous remailers, it assigns its users a user name, and it keeps a database of instructions on how to return messages to the real user. These instructions usually involve the anonymous remailer network itself, thus protecting the true identity of the user.
Primordial pseudonymous remailers once recorded enough information to trace the identity of the real user, making it possible for someone to obtain the identity of the real user through legal or illegal means. This form of pseudonymous remailer is no longer common.
David Chaum
wrote an article in 1981 that described many of the features present in modern pseudonymous remailers.
The Penet remailer
, which lasted from 1993 to 1996, was a popular pseudonymous remailer.
server") is a server
that provides an untraceable e-mail address, such that neither the nym server operator nor the operators of the remailers involved can discover which nym corresponds to which real identity.
To set up a nym, you create a PGP
keypair and submit it to the nym server, along with instructions (called a reply block) to anonymous remailer
s (such as Cypherpunk
or Mixmaster
) on how to send a message to your real address. The nym server returns a confirmation through this reply block. You then send a message to the address in the confirmation.
To send a message through the nym server so that the From address is the nym, you add a few headers, sign the message with your nym key, encrypt it with the nym server key, and send the message to the nym server, probably routed through some anonymous remailers. When the nym server gets the message, it decrypts the message and sends it on to the intended recipient, with the From: address being your nym.
When the nym server gets a message addressed to the nym, it appends it to the nym's reply block and sends it to the first remailer in the chain, which sends it to the next and so on until it reaches your real address. It is considered good practice to include instructions to encrypt it on the way, so that someone (or some organization) doing in/out traffic analysis
on the nym server cannot easily match the message received by you to the one sent by the nym server.
Existing "multi-use reply block" nym servers were shown to be susceptible to passive traffic analysis with one month's worth of incoming spam
(based on 2005 figures) in a paper by Bram Cohen
, Len Sassaman
, and Nick Mathewson.
Anonymous remailer
An anonymous remailer is a server computer which receives messages with embedded instructions on where to send them next, and which forwards them without revealing where they originally came from...
, is an Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
software program designed to allow people to write pseudonym
Pseudonym
A pseudonym is a name that a person assumes for a particular purpose and that differs from his or her original orthonym...
ous messages on Usenet
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
newsgroups and send pseudonymous email
Email
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
. Unlike purely anonymous remailers, it assigns its users a user name, and it keeps a database of instructions on how to return messages to the real user. These instructions usually involve the anonymous remailer network itself, thus protecting the true identity of the user.
Primordial pseudonymous remailers once recorded enough information to trace the identity of the real user, making it possible for someone to obtain the identity of the real user through legal or illegal means. This form of pseudonymous remailer is no longer common.
David Chaum
David Chaum
David Chaum is the inventor of many cryptographic protocols, including blind signature schemes, commitment schemes, and digital cash. In 1982, Chaum founded the International Association for Cryptologic Research , which currently organizes academic conferences in cryptography research...
wrote an article in 1981 that described many of the features present in modern pseudonymous remailers.
The Penet remailer
Penet remailer
The Penet remailer was a pseudonymous remailer operated by Johan "Julf" Helsingius of Finland from 1993 to 1996. Its initial creation stemmed from an argument in a Finnish newsgroup over whether people should be required to tie their real name to their online communications...
, which lasted from 1993 to 1996, was a popular pseudonymous remailer.
Contemporary nym servers
A nym server (short for "pseudonymPseudonymity
Pseudonymity is a word derived from pseudonym, meaning 'false name', and anonymity, meaning unknown or undeclared source, describing a state of disguised identity. The pseudonym identifies a holder, that is, one or more human beings who possess but do not disclose their true names...
server") is a server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
that provides an untraceable e-mail address, such that neither the nym server operator nor the operators of the remailers involved can discover which nym corresponds to which real identity.
To set up a nym, you create a PGP
Pretty Good Privacy
Pretty Good Privacy is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to increase the security...
keypair and submit it to the nym server, along with instructions (called a reply block) to anonymous remailer
Anonymous remailer
An anonymous remailer is a server computer which receives messages with embedded instructions on where to send them next, and which forwards them without revealing where they originally came from...
s (such as Cypherpunk
Cypherpunk anonymous remailer
A cypherpunk anonymous remailer is a Type I anonymous remailer that takes messages encrypted with PGP or GPG, or in some cases in plain text, and forwards them removing any identifying information from the header.-Sending a Cypherpunk Message:...
or Mixmaster
Mixmaster anonymous remailer
Mixmaster is a Type II anonymous remailer which sends messages in fixed-size packets and reorders them, preventing anyone watching the messages go in and out of remailers from tracing them. Mixmaster was originally written by Lance Cottrell, and was maintained by Len Sassaman Peter Palfrader is the...
) on how to send a message to your real address. The nym server returns a confirmation through this reply block. You then send a message to the address in the confirmation.
To send a message through the nym server so that the From address is the nym, you add a few headers, sign the message with your nym key, encrypt it with the nym server key, and send the message to the nym server, probably routed through some anonymous remailers. When the nym server gets the message, it decrypts the message and sends it on to the intended recipient, with the From: address being your nym.
When the nym server gets a message addressed to the nym, it appends it to the nym's reply block and sends it to the first remailer in the chain, which sends it to the next and so on until it reaches your real address. It is considered good practice to include instructions to encrypt it on the way, so that someone (or some organization) doing in/out traffic analysis
Traffic analysis
Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted and cannot be decrypted. In general, the greater the number of messages observed, or even intercepted and...
on the nym server cannot easily match the message received by you to the one sent by the nym server.
Existing "multi-use reply block" nym servers were shown to be susceptible to passive traffic analysis with one month's worth of incoming spam
Spam (electronic)
Spam is the use of electronic messaging systems to send unsolicited bulk messages indiscriminately...
(based on 2005 figures) in a paper by Bram Cohen
Bram Cohen
Bram Cohen is an American computer programmer, best known as the author of the peer-to-peer BitTorrent protocol, as well as the first file sharing program to use the protocol, also known as BitTorrent...
, Len Sassaman
Len Sassaman
Len Sassaman was an advocate for privacy, maintainer of the Mixmaster anonymous remailer code and remop of the randseed remailer.He was employed as the security architect and senior systems engineer for Anonymizer...
, and Nick Mathewson.
See also
- AnonymityAnonymityAnonymity is derived from the Greek word ἀνωνυμία, anonymia, meaning "without a name" or "namelessness". In colloquial use, anonymity typically refers to the state of an individual's personal identity, or personally identifiable information, being publicly unknown.There are many reasons why a...
- Anonymous P2PAnonymous P2PAn anonymous P2P communication system is a peer-to-peer distributed application in which the nodes or participants are anonymous or pseudonymous...
- Anonymous remailerAnonymous remailerAn anonymous remailer is a server computer which receives messages with embedded instructions on where to send them next, and which forwards them without revealing where they originally came from...
- Cypherpunk anonymous remailerCypherpunk anonymous remailerA cypherpunk anonymous remailer is a Type I anonymous remailer that takes messages encrypted with PGP or GPG, or in some cases in plain text, and forwards them removing any identifying information from the header.-Sending a Cypherpunk Message:...
(Type I) - Mixmaster anonymous remailerMixmaster anonymous remailerMixmaster is a Type II anonymous remailer which sends messages in fixed-size packets and reorders them, preventing anyone watching the messages go in and out of remailers from tracing them. Mixmaster was originally written by Lance Cottrell, and was maintained by Len Sassaman Peter Palfrader is the...
(Type II) - MixminionMixminionMixminion is the standard implementation of the Type III anonymous remailer protocol. Mixminion can send and receive anonymous e-mail.Mixminion uses a mix network architecture to provide strong anonymity, and prevent eavesdroppers and other attackers from linking senders and recipients...
(Type III) - I2P-Bote
- Cypherpunk anonymous remailer
- Onion routingOnion routingOnion routing is a technique for anonymous communication over a computer network. Messages are repeatedly encrypted and then sent through several network nodes called onion routers. Like someone unpeeling an onion, each onion router removes a layer of encryption to uncover routing instructions, and...
- Tor (anonymity network)Tor (anonymity network)Tor is a system intended to enable online anonymity. Tor client software routes Internet traffic through a worldwide volunteer network of servers in order to conceal a user's location or usage from someone conducting network surveillance or traffic analysis...
- Tor (anonymity network)
- Anonymous P2P
- Data privacyData privacyInformation privacy, or data privacy is the relationship between collection and dissemination of data, technology, the public expectation of privacy, and the legal and political issues surrounding them....
- Penet remailerPenet remailerThe Penet remailer was a pseudonymous remailer operated by Johan "Julf" Helsingius of Finland from 1993 to 1996. Its initial creation stemmed from an argument in a Finnish newsgroup over whether people should be required to tie their real name to their online communications...
- Traffic analysisTraffic analysisTraffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted and cannot be decrypted. In general, the greater the number of messages observed, or even intercepted and...
External links
- Anonymous Remailer FAQ
- Mixmaster FAQ
- Official I2P-Bote eepsite (I2P-internal)
- I2P-Bote (website accessible from the internet)
Further reading
- Email Security, Bruce SchneierBruce SchneierBruce Schneier is an American cryptographer, computer security specialist, and writer. He is the author of several books on general security topics, computer security and cryptography, and is the founder and chief technology officer of BT Managed Security Solutions, formerly Counterpane Internet...
(ISBN 0-471-05318-X) - Computer Privacy Handbook, Andre Bacard (ISBN 1-56609-171-3)