What does an Intrusion Detection System (IDS) do?

An Intrusion Detection System (IDS) is designed to monitor network traffic and system activities for signs of suspicious or unauthorized behavior. It accomplishes this by analyzing event logs and network packets to detect patterns that may indicate a security breach, such as unauthorized access attempts, unrecognized changes to critical system files, or unusual network traffic patterns.

When an IDS identifies potential threats, it may alert system administrators so they can take appropriate action to mitigate the risk. This capability is essential for maintaining the security of networks and systems, as it helps organizations respond quickly to potential intrusions, rather than solely relying on preventive measures.

The other options involve functions that are not part of the primary role of an IDS. For instance, blocking incoming traffic is typically a function of firewalls, while encrypting data pertains to protecting data in transit or at rest, which is handled by encryption protocols. Firewall protection against malware specifically aims to prevent unauthorized access and malicious software from entering a network, again not a functionality of an IDS.