VNC encrypted connection using SSH

Connect to remote host with ssh (assume vncserver is runing on 5901 port)
$ ssh -L 5902:localhost:5901 user@remotehost

Run vncviewer
$ vncviewer localhost:2


For windows using PuTTY
Add forwarded port:
Connection > SSH > Tunnels
Source port: 5902
Destination: localhost:5901
click [Add]
Connect and then run vncviewer localhost:2