What does an intrusion detection system (IDS) do?

An intrusion detection system (IDS) is primarily designed to monitor networks or systems for any signs of malicious activity or violations of security policies. This functionality is crucial for identifying potential threats such as unauthorized access attempts, breaches of data confidentiality, or abnormal behavior that could indicate an ongoing attack.

The IDS analyzes traffic patterns and system logs, looking for known attack signatures or anomalous activities that deviate from established baselines. When suspicious behavior is detected, the IDS typically alerts administrators so that they can respond to the threat timely, enhancing the overall security posture of the organization.

In contrast, monitoring software updates focuses on maintaining the latest patches for software vulnerabilities but does not actively detect intrusions. Scanning for network performance issues relates to ensuring that the network operates efficiently rather than monitoring for security threats. Encrypting sensitive data is a method of protecting data from unauthorized access but does not involve detecting intrusions or malicious activities. Thus, the primary role of an IDS is to help identify and respond to possible security incidents, aligning it perfectly with the description of monitoring networks or systems for malicious activity or policy violations.