Freenet

Freenet is free software which lets you publish and obtain information on the Internet without fear of censorship. To achieve this freedom, the network is entirely decentralized and publishers and consumers of information are anonymous. Without anonymity there can never be true freedom of speech, and without decentralization the network will be vulnerable to attack. Communications by Freenet nodes are encrypted and are "routed-through" other nodes to make it extremely difficult to determine who is requesting the information and what its content is.

Users contribute to the network by giving bandwidth and a portion of their hard drive (called the "data store") for storing files. Unlike other peer-to-peer file sharing networks, Freenet does not let the user control what is stored in the data store. Instead, files are kept or deleted depending on how popular they are, with the least popular being discarded to make way for newer or more popular content. Files in the data store are encrypted to reduce the likelihood of prosecution by persons wishing to censor Freenet content. The network can be used in a number of different ways and isn't restricted to just sharing files like other peer-to-peer networks. It acts more like an Internet within an Internet.

For example Freenet can be used for:

• Publishing websites or 'freesites'
• Communicating via message boards
• Content distribution

Unlike many cutting edge projects, Freenet long ago escaped the science lab, it has been downloaded by over 2 million users since the project started, and it is used for the distribution of censored information all over the world including countries such as China and the Middle East. Ideas and concepts pioneered in Freenet have had a significant impact in the academic world. Our 2000 paper "Freenet: A Distributed Anonymous Information Storage and Retrieval System" was the most cited computer science paper of 2000 according to Citeseer, and Freenet has also inspired papers in the worlds of law and philosophy. Ian Clarke, Freenet's creator and project coordinator, was selected as one of the top 100 innovators of 2003 by MIT's Technology Review magazine.

The features of Freenet are:

• Highly survivable: All internal processes are completely anonymized and decentralized across the global network, making it virtually impossible for an attacker to destroy information or take control of the system.
• Private: Freenet makes it extremely difficult for anyone to spy on the information that you are viewing, publishing, or storing.
• Secure: Information stored in Freenet is protected by strong cryptography against malicious tampering or counterfeiting.
• Efficient: Freenet dynamically replicates and relocates information in response to demand to provide efficient service and minimal bandwidth usage regardless of load. Significantly, Freenet generally requires log(n) time to retrieve a piece of information in a network of size.