What is IDS?

As cyberthreats continue to develop so too do the tools used to defend against them. This is both a benefit and a challenge to people involved in cybersecurity. Over the long term, (even the medium term), it makes their job easier. In the short term, however, it requires them to keep learning new tools and the skills to go with them. With that in mind, here is a brief answer to the question “What is IDS?”.

What is IDS?

A simple answer to the question “What is IDS?” is that IDS is a security mechanism designed to detect and respond to unauthorized or malicious activities within a computer system or network. Its core purpose is to identify potential security incidents, such as cyberattacks, unauthorized access, or abnormal behavior, by monitoring and analyzing system and network activities.

How an IDS works

An IDS monitors both the volume and the content of traffic. The volume can be determined by simply measuring how many data packets are transmitted per second. The content is monitored by analyzing the packet headers. This analysis generally uses three main strategies.

Signature-based detection: This method involves comparing observed patterns with known signatures of known threats. If a match is found, the IDS generates an alert.

Anomaly-based detection: IDS establishes a baseline of normal network behavior and triggers alerts when deviations, or anomalies, are detected. This method is effective against novel or evolving threats.

Heuristic-based detection: Heuristic analysis involves identifying patterns or behaviors that may indicate a potential threat. It allows IDS to detect previously unknown threats based on suspicious characteristics.

IDS vs. Other security tools

Another way to answer the question “What is IDS?” is to look at how it compares to other common IT security tools.

IDS vs. Intrusion Prevention Systems

Possibly the single biggest reason why people ask “What is IDS?” is that IDS sounds very similar to IPS. IPS is also a popular IT security tool. If, however, you take a closer look at the names, the difference between them becomes more obvious.

IDS stands for Intrusion Detection System. An IDS passively monitors and analyzes network traffic for suspicious activity. If it detects any, it generates alerts but does not respond itself. IPS stands for Intrusion Prevention System. An IPS both alerts and acts to defend against identified threats.

The fact that IDS requires direction from another tool or a human means that it is only effective when working under fairly close supervision. On the flip side, the fact that it works under supervision means that false positives tend to be a minor issue with IDS.

In contrast, an IPS can work under less direct supervision. It does, however, require careful management to minimize false-positives.

IDS vs. Firewalls

The difference between IDS and firewalls is much the same as the difference between IDS and IPS. An IDS passively monitors and analyzes network traffic and alerts to potential threats. A firewall actively controls network traffic in accordance with predetermined security rules. For completeness, the key difference between an IPS and a firewall is that an IPS is placed inside the network. A firewall is placed at its perimeter.

IDS vs. Antivirus software

An IDS monitors for the presence of malware (amongst other threats). It does not actively work to remove the threat. By contrast, the specific purpose of antivirus software is to detect and remove malware.

Furthermore, an IDS can be placed in several different locations in a network or in a cloud. Antivirus tends to need to have some presence on a host device even if most of the work is undertaken in the cloud.

Another key point of difference is that antivirus software tends to lean heavily into signature-based detection systems. In other words, they are very dependent on recognizing pre-defined patterns. IDS do use signature-based detection methods but they are not usually dependent on them. For example, they will often use anomaly detection, and heuristic detection (problem-solving) as well.

IDS vs. Security Information and Event Management (SIEM) systems

An IDS is used for real-time threat detection within a network. It actively monitors network traffic, looking for patterns indicative of unauthorized activities. A SIEM collects data from multiple sources, including IDS, firewalls, and antivirus tools. It correlates and analyzes this data to provide a comprehensive view of an organization’s security landscape.

The fact that an SIEM uses data from multiple sources means that it operates at a much slower pace than an IDS. It is therefore of relatively little use for dealing with threats in progress. By contrast, it can be invaluable for the long-term analysis of security events. In particular, it can help a lot with the identification of persistent threats or patterns of behavior that may span an extended period.

Related Resource:

What Is Ids Definition
What Is An Ids Def
Understanding Ips Meaning And Significance
Ips Security Safeguarding Networks From Cyber Threats
An Overview Of Ids Ips Compared