In what way does an anomaly-based IDS differ from a signature-based IDS?

Anomaly-based Intrusion Detection Systems (IDS) stand out from signature-based IDS by focusing on identifying deviations from established patterns of normal behavior within the network. This method involves creating a baseline of what is considered "normal" traffic and activities. When the system detects behaviors or patterns that significantly deviate from this baseline, it can raise alerts or take action. This is effective in recognizing new, unknown threats that do not yet have a known signature.

In contrast, signature-based systems rely on a predefined set of known threats, utilizing specific patterns (or signatures) to detect intrusions. This makes them highly effective at identifying known vulnerabilities and attacks but less capable of catching novel threats that do not match any existing signatures. Anomaly detection allows for a more dynamic approach to threat detection, adapting to changing network conditions and uncovering potential security incidents that signature-based methods might miss.