http://tttyx2vwp7ihml3vkhywwcizv6nbwrikpgeciy3qrow7l7muak2pnhad.onion/Publications.html
This second-generation Onion Routing system addresses
limitations in the original design by adding perfect forward secrecy,
congestion control, directory servers, integrity checking,
configurable exit policies, and a practical design for location-hidden
services via rendezvous points.