Air Gap

Air Gap: A security principle in which a system is physically or logically separated from other networks. The concept shapes security architectureSecurity ArchitectureThe structured design of security controls, trust boundaries, data flows, and operational responsibilities. and systematically reduces opportunities for attack or lateral movement. It should be planned based on risk, documented, tested, and regularly adjusted.

How it works and where it fits

Air Gap is a preventive, detective, or corrective security control. Its effect depends on where it sits in the architecture, which data and decisions it processes, and how it might be bypassed. A control reduces a defined risk but rarely removes it completely, so it should be combined with additional layers of protection.

Practical security relevance

Before deployment, the objective, ownership, coverage, and expected behavior should be defined. Secure defaults, controlled exceptions, logging, and periodic effectiveness tests matter more than installation alone. Operational metrics should expose both blocked or detected activity and gaps, false alerts, and effects on legitimate business processes.

Related concepts

• Unidirectional GatewayUnidirectional GatewaySecurity component that technically permits data traffic in only one direction.: Security component that technically permits data traffic in only one direction.
• Network SegmentationNetwork SegmentationSeparates network segments to control access and limit lateral movement.: Separates network segments to control access and limit lateral movement.
• Operational Technology SecurityOperational Technology SecurityProtects industrial control, production, and process control systems.: Protects industrial control, production, and process control systems.
• Defense in DepthDefense in DepthCombines multiple independent security controls to create layered protection.: Combines multiple independent security controls to create layered protection.