Intrusion Detection System Definition

KZero Staff
Jul 27, 2023

What is an Intrusion Detection System (IDS)?

Intrusion detection systems (IDS) are security tools designed to identify malicious content or policy violations in network traffic. These systems inspect network traffic and attempt to identify known malware, malicious activities, or anomalies that might indicate a cybersecurity incident.

How Does an IDS Work?

An IDS is a security solution that identifies and alerts on potential threats in network traffic. An IDS can use a few different techniques to detect these potential threats to the organization, including:

  • Signature-Based: Signature-based IDS identify known malware based on unique signatures. This offers detection with low false positives but misses zero-day threats.
  • Anomaly-Based: Anomaly-based IDS uses machine learning or statistical analysis to identify anomalous network traffic. These deviations from normal can indicate a potential security threat.
  • Policy-Based: IDS solutions can be used to enforce corporate security policies. Policy-based IDS will flag any actions that violate pre-defined corporate security policies.
  • Heuristic-Based: Heuristic-based analysis uses algorithms to identify potential threats. This attempts to identify attacks based on unusual patterns.


An IDS and an intrusion prevention system (IPS) have similar functions. In fact, they can be the same solution but differ in how they handle identified threats.

An IDS is designed to alert security personnel if a threat is identified, but it allows the malicious traffic to continue on. An IPS, on the other hand, has the ability to block identified threats, protecting the organization against the potential threat.

Benefits of IDS

An IDS is designed to identify and generate alerts regarding potential threats to the organization. IDS solutions provide various potential benefits to an organization, including the following:

  • Ongoing Monitoring: An IDS will inspect traffic as it flows through an organization’s network. This enables it to detect attacks as they happen and supports rapid incident response.
  • Alerts and Notifications: After identifying a threat, an IDS generates an alert for security personnel. These alerts can be performed via email, logs, or integrations with an organization’s existing ticketing infrastructure.
  • Logging: In addition to generating alerts, an IDS will create logs recording the observed events. These logs can be useful when performing forensic analysis of an incident after the fact.
  • Security Integration: An IDS can be integrated with other solutions in an organization’s security architecture. For example, a next-generation firewall (NGFW) commonly includes IDS functionality.
  • Threat Intelligence Ingestion: An IDS can ingest threat intelligence data from feeds that an organization subscribes to. This enables it to identify the latest attacks and threats to the organization.


An IDS is a cybersecurity solution designed to identify and alert on potential threats to the organization. It does so by monitoring network traffic and using various techniques to detect known threats or anomalies that can indicate a potential cyberattack. IDS differ from IPS because an IDS will simply generate an alert when it detects a threat, while an IPS will block the malicious traffic

IDS systems can provide various benefits to the organization and can identify cyberattacks early in their lifecycles. However, they can be resource-intensive to use and may generate false positive detections.

KZero Staff

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