VNC^® Enterprise Edition User Guide

Uniquely identifying VNC Server

VNC Server has a signature uniquely identifying it.

•  Under Windows and Mac OS X, the signature uniquely identifies VNC Server among all instances running on the same host computer.

•  Under UNIX or Linux, the signature is shared by instances of VNC Server started by the same host computer user.

A VNC Server signature is displayed in the VNC Server Status dialog:

(Windows XP)

When a user connects from a particular client computer for the first time, this signature is published. The user is asked to verify it in order to continue connecting:

A connecting user may be able to check that the published signature matches that of VNC Server, for example if a host computer user is present, or if the connecting user set up VNC Server in the first place.

A VNC Server signature should not change. The next (and all subsequent) times a user connects from the same client computer, the signature is not published. If the signature changes, it may be because a third party is interrupting the connection between client and host computers and eavesdropping on communications – a so-called ‘man-in-the-middle’ attack. If a user sees a message similar to the following:

then it is recommended that they do not continue connecting.

Note: The signature does change if VNC Server is re-installed on the host computer.