What is an air gap in cybersecurity?
D3 · Architecture · CompTIA Security+ SY0-701An air gap is a physical security measure that completely isolates a computer system or network from the internet and all other unsecured networks — there is literally an air gap (physical separation) between them with no electronic connection.
Used for: nuclear facility controls, classified government networks, industrial control systems (ICS/SCADA), election systems, military systems.
Air gap bridging attacks: USB drops (Stuxnet used USB to bridge an air gap), acoustic attacks, electromagnetic emanations (TEMPEST), optical attacks (blinking LEDs).
Used for: nuclear facility controls, classified government networks, industrial control systems (ICS/SCADA), election systems, military systems.
Air gap bridging attacks: USB drops (Stuxnet used USB to bridge an air gap), acoustic attacks, electromagnetic emanations (TEMPEST), optical attacks (blinking LEDs).
Air gaps provide the strongest network isolation — but are not foolproof. Stuxnet famously crossed an air gap via infected USB drives. Insider threats and supply chain attacks can bridge air gaps. Air gapped systems still need physical security, removable media controls, and strict access procedures.