Network Defense Essentials (NDE) Practice Exam

Which IDS detection method involves creating models of possible intrusions to compare with incoming events?

1. Signature recognition

2. Anomaly detection

3. Behavioral detection

4. Network traffic analysis

The correct answer is: Signature recognition

The key to understanding the correct choice lies in recognizing the nature of anomaly detection in Intrusion Detection Systems (IDS). Anomaly detection methods operate by establishing a baseline of normal behavior within a network or system. This baseline is created through the collection and modeling of historical data, allowing the detection system to identify deviations from expected patterns or behaviors. When incoming events deviate significantly from the established baseline, these anomalies can indicate potential security threats or intrusions. Thus, the strength of this method lies in its capability to recognize novel or unexpected attack patterns that may not have been previously identified or documented. In contrast, signature recognition focuses on identifying known threats based on specific patterns or signatures of malware, which does not involve modeling future possibilities but rather matching against known entities. Behavioral detection overlaps somewhat with anomaly detection but is more aligned with specific user or system behaviors, rather than the broader context of network traffic. Lastly, network traffic analysis refers to the assessment of data traffic patterns without necessarily predicting or modeling possible intrusions. Understanding these distinctions clarifies why anomaly detection is the correct answer regarding the creation and comparison of models for identifying potential intrusions.