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.
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.
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.
A darknet or dark net is an overlay network within the Internet that can only be accessed with specific software, configurations, or authorization, and often uses a unique customized communication protocol. Two typical darknet types are social networks, and anonymity proxy networks such as Tor via an anonymized series of connections.
The Free Haven Project was formed in 1999 by a group of Massachusetts Institute of Technology students with the aim to develop a secure, decentralized system of data storage. The group's work led to a collaboration with the United States Naval Research Laboratory to develop Tor, funded by DARPA.
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.
In anonymity networks, it is important to be able to measure quantitatively the guarantee that is given to the system. The degree of anonymity is a device that was proposed at the 2002 Privacy Enhancing Technology (PET) conference. Two papers put forth the idea of using entropy as the basis for formally measuring anonymity: "Towards an Information Theoretic Metric for Anonymity", and "Towards Measuring Anonymity". The ideas presented are very similar with minor differences in the final definition of .
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.
Tribler is an open source decentralized BitTorrent client which allows anonymous peer-to-peer by default. Tribler is based on the BitTorrent protocol and uses an overlay network for content searching. Due to this overlay network, Tribler does not require an external website or indexing service to discover content. The user interface of Tribler is very basic and focused on ease of use instead of diversity of features. Tribler is available for Linux, Windows, and OS X.
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.
Tor is a free overlay network for enabling anonymous communication. Built on free and open-source software and more than seven thousand volunteer-operated relays worldwide, users can have their Internet traffic routed via a random path through the network.
Whonix is a Linux distribution, based on Kicksecure OS, claimed to be security hardened by its developers.
The Tor Project, Inc. is a 501(c)(3) research-education nonprofit organization based in Winchester, Massachusetts. It is founded by computer scientists Roger Dingledine, Nick Mathewson, and five others. The Tor Project is primarily responsible for maintaining software for the Tor anonymity network.
Roger Dingledine is an American computer scientist known for having co-founded the Tor Project. A student of mathematics, computer science, and electrical engineering, Dingledine is also known by the pseudonym arma. As of December 2016, he continues in a leadership role with the Tor Project, as a project Leader, Director, and Research Director.
Paul Syverson is a computer scientist best known for inventing onion routing, a feature of the Tor anonymity network.
Hard privacy technologies are methods of protecting data. Hard privacy technologies and soft privacy technologies both fall under the category of privacy-enhancing technologies. Hard privacy technologies allow online users to protect their privacy through different services and applications without the trust of the third-parties. The data protection goal is data minimization and reduction of the trust in third-parties and the freedom to conceal information or to communicate.
The Nym mixnet is a free and open-source software designed to ensure a high level of privacy in all online communications. It is an implementation of a mix network devised by David Chaum in 1981.
