Email is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.
A cypherpunk is one who advocates the widespread use of strong cryptography and privacy-enhancing technologies as a means of effecting social and political change. The cypherpunk movement originated with the establishment of an electronic mailing list, through which informal groups sought to achieve privacy and security through proactive use of cryptography. The cypherpunk movement has been active since about 1990 at the latest.
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. It is an implementation of a David Chaum's mix network.
An anonymous remailer is a server that receives messages with embedded instructions on where to send them next, and that forwards them without revealing where they originally came from. There are cypherpunk anonymous remailers, mixmaster anonymous remailers, and nym servers, among others, which differ in how they work, in the policies they adopt, and in the type of attack on the anonymity of e-mail they can resist. Remailing as discussed in this article applies to e-mails intended for particular recipients, not the general public. Anonymity in the latter case is more easily addressed by using any of several methods of anonymous publication.
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. Julf believed that people should not—indeed, could not—be required to do so. In his own words:
A pseudonymous remailer or nym server, as opposed to an anonymous remailer, is an Internet software program designed to allow people to write pseudonymous 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.
Various anti-spam techniques are used to prevent email spam.
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 the layers of an onion. The encrypted data is transmitted through a series of network nodes called "onion routers," each of which "peels" away a single layer, revealing the data's next destination. When the final layer is decrypted, the message arrives at its destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes. While onion routing provides a high level of security and anonymity, there are methods to break the anonymity of this technique, such as timing analysis.
An anonymous P2P communication system is a peer-to-peer distributed application in which the nodes, which are used to share resources, or participants are anonymous or pseudonymous. Anonymity of participants is usually achieved by special routing overlay networks that hide the physical location of each node from other participants.
Johan "Julf" Helsingius, born in 1961 in Helsinki, Finland, started and ran the Anon.penet.fi internet remailer.
Email authentication, or validation, is a collection of techniques aimed at providing verifiable information about the origin of email messages by validating the domain ownership of any message transfer agents (MTA) who participated in transferring and possibly modifying a message.
Java Anon Proxy (JAP) also known as JonDonym, was a proxy system designed to allow browsing the Web with revocable pseudonymity. It was originally developed as part of a project of the Technische Universität Dresden, the Universität Regensburg and Privacy Commissioner of the state of Schleswig-Holstein. The client-software is written in the Java programming language. The service has been closed since August 2021.
Mixminion is the standard implementation of the Type III anonymous remailer protocol. Mixminion can send and receive anonymous e-mail.
Email tracking or email tracker is a method for monitoring whether the email message is read by the intended recipient. Most tracking technologies use some form of digitally time-stamped record to reveal the exact time and date when an email is received or opened, as well as the IP address of the recipient.
Mix networks are routing protocols that create hard-to-trace communications by using a chain of proxy servers known as mixes which take in messages from multiple senders, shuffle them, and send them back out in random order to the next destination. This breaks the link between the source of the request and the destination, making it harder for eavesdroppers to trace end-to-end communications. Furthermore, mixes only know the node that it immediately received the message from, and the immediate destination to send the shuffled messages to, making the network resistant to malicious mix nodes.
Garlic routing is a variant of onion routing that encrypts multiple messages together to make it more difficult for attackers to perform traffic analysis and to increase the speed of data transfer.
An anonymizer or an anonymous proxy is a tool that attempts to make activity on the Internet untraceable. It is a proxy server computer that acts as an intermediary and privacy shield between a client computer and the rest of the Internet. It accesses the Internet on the user's behalf, protecting personal information of the user by hiding the client computer's identifying information such as IP addresses. Anonymous proxy is the opposite of transparent proxy, which sends user information in the connection request header. Commercial anonymous proxies are usually sold as VPN services.
Privacy-enhancing technologies (PET) are technologies that embody fundamental data protection principles by minimizing personal data use, maximizing data security, and empowering individuals. PETs allow online users to protect the privacy of their personally identifiable information (PII), which is often provided to and handled by services or applications. PETs use techniques to minimize an information system's possession of personal data without losing functionality. Generally speaking, PETs can be categorized as either hard or soft privacy technologies.
Harold Thomas Finney II was an American software developer. In his early career, he was credited as lead developer on several console games. He later worked for PGP Corporation. He was an early Bitcoin contributor, and received the first Bitcoin transaction from the currency's creator Satoshi Nakamoto.
Invisible mail, also referred to as iMail, i-mail or Bote mail, is a method of exchanging digital messages from an author to one or more recipients in a secure and untraceable way. It is an open protocol and its java implementation (I2P-Bote) is free and open-source software, licensed under the GPLv3.
