It's just that simple.
Amid all the fury over the release of Firesheep, no one else seems to have noticed, or at least mentioned, that the only thing any WiFi hotspot needs to do to protect its users is activate WPA encryption using any simple publicly-known password.
As long as the universally supported WPA encryption protocol is used, each individual user receives their own private “session key” that absolutely prevents eavesdropping between users, even through they are all using the same WiFi password. It’s just that simple.
Hotspots only need to switch from “no encryption” to WPA and post or publish any static WPA password … and a large part of the problem, and more, is solved.
Read more at steve.grc.com