- User Guide
This is not the most recent version. Read the latest documentation.
VNC Server (Enterprise) and VNC Server (Personal) have a uniquely identifying signature:
• Under Windows and Mac OS X, this signature uniquely identifies VNC Server among all instances running on the same host computer.
• Under UNIX/Linux, this signature is shared by instances of VNC Server started by the same host computer user.
Note: VNC Server (Free) does not have a unique signature. Upgrade the host computer to VNC Server (Enterprise) or VNC Server (Personal) if security is important to you.
The VNC Server signature is displayed in the Get Started area of the VNC Server dialog. More on this dialog.
When a user connects from a particular client computer for the first time, this signature is published. The user is asked to verify that the signature they see matches that of VNC Server. See Checking the signature for more information.
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:
WARNING: VNC Server’s signature has changed since you last connected to it.
Unless there is a good reason for the signature to have changed, you should not continue connecting.
The new VNC Server signature is fa-a5-76-c9-3d-df-ca-1d.
Do you wish to accept the new signature and continue connecting?
then it is recommended that they do not connect.
Note: The signature does change if VNC Server is re-installed on the host computer.