Unidirectional gateways are network devices that allow data to be transmitted in one direction only. Unlike a firewall, the security is hardware-based, making it physically impossible to send data back in the reverse direction. By having separate devices to transmit (TX) and receive (RX) data, the network security boundary becomes clearly defined and user anxiety is eliminated. When deployed in critical infrastructure such as power plants, it not only protects the facility network from cyber-attacks, but also allows huge amounts of data to be safely shared for monitoring and faster maintenance.