"The core principle of Tor, "onion routing", was developed in the mid-1990s by United States Naval Research Laboratory employees, mathematician Paul Syverson, a

"The core principle of Tor, "onion routing", was developed in the mid-1990s by United States Naval Research Laboratory employees, mathematician Paul Syverson, and computer scientists Michael G. Reed and David Goldschlag, with the purpose of protecting U.S. intelligence communications online. Onion routing was further developed by DARPA in 1997." - wiki on Tor