What does an intrusion-detection system do?
- Encodes files so outsiders cannot read them
- Recovers files that a user deleted by mistake
- Signals possible unauthorized access and logs events
- Blocks every message that arrives from outside
Show answer and solution
Correct answer: C. Signals possible unauthorized access and logs events
1. Companies monitor network activity with intrusion-detection systems.
2. Those systems signal possible unauthorized access.
3. They also document suspicious events for later examination.
4. Encoding is done by encryption and blocking is done by firewalls, so those roles belong elsewhere.
_Source: OpenStax Introduction to Business (CC BY 4.0), Ch 13 "Using Technology to Manage Information", section 13.5 Procedures to Protect IT Assets_