How to Configure RealVNC to Connect to CyberKey
Overview
For CyberKey to successfully connect to a RealVNC server, it is necessary to configure RealVNC to use VNC Password authentication and allow connections from legacy clients.
CyberKey uses the standard VNC protocol (RFB) and does not support proprietary RealVNC authentication methods such as cloud account authentication or SSO.
Technologies Involved
- CyberKey – Cybervision
- RealVNC Server
1. Configure Authentication in RealVNC
Open VNC Server on the machine that will be accessed.
Go to:
Menu → Options → Security
Change the configuration:
- Authentication: → VNC password
- Encryption: You can leave it as Prefer On or Always On
Example of the correct configuration:
Why is this necessary?
CyberKey:
- ❌ Does not authenticate using a RealVNC Cloud account
- ❌ Does not use SSO
- �
Uses traditional VNC password authentication (RFB protocol)
2. Set the VNC Password
After selecting VNC password, click to define the password.
Enter:
- Password
- Confirm password
⚠ Important: This password will be used when creating the connection inside CyberKey.
VNC password configuration screen:
3. Enable “Allow connections from legacy VNC Viewer users”
Check the option:
☑ Allow connections from legacy VNC Viewer users
Why is this essential?
CyberKey uses the standard VNC protocol (RFB) and identifies itself as a traditional VNC client.
If this option is not enabled:
- The RealVNC server will reject the connection
- Authentication errors may occur
- Security negotiation failures may appear
4. Configuration in CyberKey
Inside the CyberKey panel:
Connections → Add
Protocol: VNC
Configure:
- Hostname: Server IP address
- Port: 5900 (or custom port if configured)
- Password: The VNC password configured in RealVNC
- Username: Not required
5. Common Issues
| Error | Probable Cause |
|---|---|
| Authentication failed | Incorrect VNC password |
| Connection refused | Port 5900 blocked |
| No supported authentication methods | Legacy option not enabled |
| Timeout | Firewall blocking connection |
