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What is An Intrusion Detection System?

What is An Intrusion Detection System?

Just as a physical building must be secured from intruders, so too must a digital network. Once they gain covert entry into a particular system and/or network, cyber attackers have proven capable of many forms of hijacking. Basically, anything that you can do on a computerized device has the potential to be hijacked (taken over) by someone else. However, before that can happen, they have to figure out some way to make a covert entry in the first place. That’s why an intrusion detection system is so important.

What Is An Intrusion Detection System?

An intrusion detection system (hereafter referred to as an IDS) is a piece of software or hardware that is intended to monitor traffic for signs of intrusion. As the name tells you, an IDS is basically an intruder alarm. Its primary purpose is to detect suspicious patterns and send an alert to the authorized user.

IDS systems can detect activity in a number of ways, but the most important tool is probably network security monitoring software. Without this, it would be impossible for the IDS program to see network traffic at a fundamental level. An IDS system is basically a combination of a network monitor and an auto-analysis tool.

Different Methods Of Detection

An IDS program needs to cover every aspect of your system, and that’s why it tends to be divided into two halves. NIDS (Network Intrusion Detection Systems) operate in the way described in the previous section. These operations are definitely more important because most attacks begin at the network level.

That being said, HIDS (Host Intrusion Detection Systems) is important as the second line of defense. These will monitor important system files and any other data that is deemed a likely target. Although they have many ways of attacking, most hackers will tend to attack the same parts of a particular system. In the case of a physical-access data breach, this may be your only opportunity for detection.

So, how does your IDS software define and categorize something as a “threat?” This can be done in one of two ways. Signature-based detection will rely on specific patterns that have been observed in the past. This is kind of like the way in which an antivirus program works, but this should be more thorough because it isn’t just looking for software signatures. Instead, it is looking for any specific data or events that match with known patterns of attack.

Anomaly-based detection is the other way in which a potential threat is categorized. Software like this will not look for specific signatures (in terms of software or behavior). Instead, they will send alerts regarding any anomalous behavior. Thus, anything out of the ordinary will be reported. These systems can protect against a wider range of threats but will give more false positives. For the record, there are some programs that will combine signature-based and anomaly-based methods.

Choosing The Best Intrusion Detection System

It is important to look for a full-featured IDS that will do more than simply issue an alert. First of all, you want something with full SIEM capability so that it can incorporate data from all parts of your system/network. You also want something that can respond to a detected attack in some way. Even if they can’t stop the attack dead in its tracks, there should be some mitigation features.

It is also important to get your IDS from a company that offers good support. Thus, you won’t have to rely completely on the technology itself. If something goes wrong or if things are just unclear, prompt and efficient customer service can make a world of difference. Finally, it is probably a good idea to look for an IDS that incorporates a dedicated AI. This allows for a level of deep analysis that would never be possible with machine learning alone. Besides, it is more difficult for a potential attacker to fool an AI because it isn’t just doing a “scan and compare” operation.


If you or your organization have a need to protect highly confidential data or extremely critical systems, an IDS is something that you need. It’s a lot more efficient than trying to get your IT team to monitor network traffic on a 24/7 basis, that’s for sure! If you are looking for local managed IT services, or if you just want to learn more about intrusion defense, feel free to call PCH Technologies at (856) 754-7500. We have plenty of well-trained and competent individuals on call who are always ready to help.