CompTIA SecurityX (CAS-005)Security EngineeringEasy
A critical infrastructure organization is integrating a new Industrial Control System (ICS) into its existing network. Due to the extreme sensitivity of the ICS and the potential for severe physical consequences from cyberattacks, the security team needs to ensure that data can flow ONLY from the ICS network to the enterprise network, with absolutely no possibility of data flowing back into the ICS network. Which specialized security device is BEST suited for this unidirectional data transfer requirement?
- AProxy Server
- BIntrusion Prevention System (IPS)
- CFirewall
- DData Diode
Show answer & explanationAnswer & explanation
Correct answer: D. Data Diode
A data diode (also known as a unidirectional gateway) is a specialized network device that physically ensures data can only flow in one direction. It is designed to create an absolute air gap in one direction, making it ideal for highly sensitive environments like ICS networks where inbound data flow is strictly prohibited to prevent attacks.
Why the other options are wrong
- A. A proxy server acts as an intermediary for requests and can be bidirectional, offering no physical one-way guarantee.
- B. An IPS detects and prevents attacks but does not physically enforce unidirectional data flow.
- C. A firewall can filter traffic but is fundamentally bidirectional and can be misconfigured or bypassed.
Data Diode (Unidirectional Gateway)
A hardware device that enforces one-way data flow between two networks. It physically prevents any data from traversing in the reverse direction, providing extreme security for critical systems.
- Physically enforces unidirectional data flow.
- Creates an absolute air gap in one direction.
- Ideal for ICS/OT and other highly sensitive networks.
Memory trick: A DATA DIODE is like a one-way street for data.