CompTIA SecurityX (CAS-005)Security EngineeringMedium
A critical infrastructure organization is implementing a new Industrial Control System (ICS) in a highly sensitive operational environment. The security architect needs to ensure that data flows from the ICS network to the enterprise network are strictly unidirectional to prevent any potential back-channel attacks or unauthorized commands from reaching the control systems. Which of the following security devices is BEST suited to enforce this requirement?
- AFirewall
- BData Diode
- CIntrusion Prevention System (IPS)
- DProxy Server
Show answer & explanationAnswer & explanation
Correct answer: B. Data Diode
A data diode (or unidirectional gateway) is a hardware device that physically enforces one-way data flow, making it impossible for data to travel in the reverse direction. This is ideal for highly sensitive environments like ICS where strict isolation is paramount.
Why the other options are wrong
- A. A firewall filters traffic based on rules but can allow bidirectional communication if configured, which doesn't guarantee strict unidirectional flow.
- C. An IPS detects and prevents intrusions but does not inherently enforce physical unidirectional data flow.
- D. A proxy server acts as an intermediary for requests and can allow bidirectional communication, not enforcing a physical one-way flow.
Data Diode (Unidirectional Gateway)
A hardware device that ensures data can only flow in one direction, physically preventing any return path. It's used for strict network segmentation.
- Physical enforcement of one-way data flow
- Prevents back-channel attacks
- Common in highly secure or critical infrastructure environments
Memory trick: Diode: Data Only In One Direction.