What is the function of an Intrusion Detection System (IDS)?

An Intrusion Detection System (IDS) is designed primarily to monitor network traffic for suspicious activity. Its core function is to analyze incoming and outgoing network packets to identify patterns or behaviors that may indicate an intrusion or security breach. This involves using predefined rules and anomaly detection techniques to flag any unusual or unauthorized activities. By effectively monitoring network traffic, an IDS can provide alerts to security personnel about potential threats, allowing them to take timely action to prevent or mitigate attacks.

In contrast, the other options describe functions that are not within the primary scope of an IDS. Data encryption is a security process that protects data integrity and confidentiality, while user authentication enhances security by verifying users’ identities before granting access to systems or data. Optimizing network performance refers to improving the efficiency and speed of network operations, which is outside the realm of what an IDS typically addresses. Therefore, distinguishing the IDS's specific purpose as a monitoring tool is crucial to understanding its role in network security.