Definition - What does Air Gap mean?
An air gap is also known as an air wall.
Techopedia explains Air Gap
An air gap is the maximum protection between a system and other device/system - apart from actually turning it off. Two disconnected systems or devices designate security levels as low side (unclassified) and high side (classified). To move data, it often must to be saved in some type of transportable medium. Moving data from low to high side is simple, whereas moving classified data from a high to low side security device requires a strict procedure prior to performing the transfer, due to the data's classified nature.
The usual configuration of an air gap is a sneakernet, in which alternate storage, like flash drives or CDs, must be used to transfer data to and from the isolated device, rather than simply moving data across shared drives and networks.
A system or device may require certain limitations, such as:
- Totally banning local wireless communications
- Preventing electromagnetic (EM) leakage by placing the system/device in a Faraday cage to block wireless transmissions
Systems that implement air gap security include nuclear power plant controls, military networks and computerized medical equipment.