VNC® technical specifications

Security features

All license types unless otherwise stated:

Authentication mechanisms to prevent unauthorized access (one mechanism for Free, two for Personal, three for Enterprise). Note authentication credentials are never sent in the clear.
Unique signature generated from a 2048-bit RSA public/private key pair to allow connecting users to verify identity. Signature changes are flagged, deterring man-in-the-middle attacks (Personal and Enterprise only).
Encrypted connections to prevent packet sniffing and tampering (128-bit AES for Personal, 256-bit AES for Enterprise, not available for Free).
Blacklisting to prevent denial-of-service attacks.
IP filtering to restrict the range of computers permitted to connect.
VNC permissions to restrict access to remote control features while connections are in progress (Personal and Enterprise only).
Access control to enable a VNC Server user to accept or reject connections.
View only connections.
Idle timeout to terminate non-responsive connections.
Exclusive access (that is, disallow concurrent connections).
Lock or log off on last disconnect to prevent unauthorized access to the VNC Server computer (Windows only).
Screen blanking to prevent unauthorized observation of the VNC Server computer (Windows only).
VNC/HTTP port sharing to minimize firewall exceptions.
Audit logging.
Signed binaries identifying RealVNC Ltd (Windows only).
Policy support (UNIX/Linux only).

x86 and x64 architectures supported, where available:

Universal architecture supported:

Connections enabled from the following products without configuration:

To enable connections to Personal or Enterprise from third-party VNC-compatible Viewer projects, turn off encryption and system authentication.

Windows

Mac OS X

UNIX/Linux

VNC Server can be started in different modes, enabling connections in different states, and for different purposes. More information…