http://tttyx2vwp7ihml3vkhywwcizv6nbwrikpgeciy3qrow7l7muak2pnhad.onion/History.html
Realtime mixing is added
to the design in the middle of Spring 1996 and does not disappear
again until generation 2. 1996: Another early discussion idea that was not reflected in published or
deployed design till much later: Discussion in April and May of using
DH keys rather than sending the onion key.