What is Intrusion detection system IDS?

Understanding Intrusion detection system IDS

A solution that monitors the environment and automatically recognizes malicious attempts to gain unauthorized access. An IDS is a device or software application that monitors networks or systems for malicious activities or policy violations, generating alerts when suspicious activities are detected. Unlike IPS, traditional IDS systems detect but do not automatically block threats. They may be network-based, host-based, or distributed. IDS capabilities are addressed in standards like NIST SP 800-94 and ISO 27001 control frameworks. Organizations implement IDS through strategic sensor placement, signature and anomaly-based detection, correlation with other security data, and integration with security operations. For example, a financial institution might deploy network-based IDS sensors at critical network boundaries to monitor for known attack patterns, suspicious traffic flows, and policy violations, feeding alerts to a SIEM system for correlation and analysis by security analysts. Related terms: Intrusion Prevention System IPS, NIDS, HIDS, Signature-based detection, Anomaly-based detection, False positive, Security monitoring, SIEM.