References

Current research

• Tor Project | Research.

Historical

• Onion Routing: the onion-router.net site formerly hosted at the Center for High Assurance Computer Systems of the U.S. Naval Research Laboratory. It primarily covers the work done at NRL during the first decade of onion routing and reflects the onion-router.net site roughly as it existed circa 2005. As a historical site it may contain dead external links and other signs of age.
• Free Haven's Selected Papers in Anonymity lists the most relevant papers that lead to Onion Services development.
• The Once and Future Onion: includes a historic overview of Onion Services technology.