How can I tunnel my connection to x11vnc via an encrypted SSH channel between two Unix machines?
See the description earlier on this page on how to tunnel VNC via SSH from Unix to Unix. A number of ways are described along with some issues you may encounter. Other secure encrypted methods exists, e.g. stunnel, IPSEC, various VPNs, etc. See also the Enhanced TightVNC Viewer (SSVNC) page where much of this is now automated.