airgapped

An airgapped system or air gap refers to a computer or network that is physically isolated from unsecured networks, notably the internet. Such isolation makes unauthorized remote access more difficult and is intended to reduce risk of cyberattack. In practice, air gaps are maintained by removing network connections and disabling wireless interfaces, with only controlled, manual data transfer allowed.

Airgapped environments are used in high-security settings such as military and intelligence facilities, critical infrastructure, financial trading floors, and data centers handling sensitive information. They commonly rely on strict security policies, access controls, and air-gap engineering. For connectivity needs, organizations employ controlled data transfer methods, such as dedicated removable media or one-way transfer devices, and in some cases data diodes.

Despite isolation, airgapped systems are not inherently immune to compromise. Attack vectors include supply chain compromise, insider threats, and targeted malware that finds a foothold via removable media; once inside, lateral movement can occur by other methods. In addition, covert channels leveraging physical emissions (sound, light, heat, electromagnetic signals) have been demonstrated in research settings. Historical cases, notably the Stuxnet worm, showed how removable media could introduce malware into air-gapped facilities.

Mitigation strategies include strict control of removable media, use of validated and scanned software, physical security, and the deployment of unidirectional data transfer devices (data diodes) when external data flow is required. Overall, the concept emphasizes defense in depth and the limits of physical isolation as a sole security measure.