Exploring Intrusion Detection
What is intrusion detection?
Intrusion Detection Systems (IDS) monitor the traffic flowing through your network and sound an alarm when they spot suspicious network activity. There are primarily two types of IDS:
- Network Intrusion Detection Systems (NIDS): NIDS monitors the entire network, looking out for abnormal patterns or activities. NIDS is the go-to choice for broad coverage, and is well-suited for larger organizations that need to monitor vast networks with many devices. However, it might miss granular-level anomalies that could indicate a threat.
- Host Intrusion Detection Systems (HIDS): HIDS, on the other hand, can cater to these granular-level needs, zeroing in on each devices activities in a network. It's a suitable choice for smaller organizations or specific high-security areas within a larger network. Though HIDS provides a meticulous, device-level analysis, managing a HIDS for numerous devices can be resource-intensive.
How does intrusion detection work?
Underneath the hood, IDS functions using one of the two primary detection methods:
- Signature-Based Detection: Think of signature based detection as matching fingerprints at a crime scene - checking network activity against a database of known threat patterns or 'signatures'. However, signature-based detection can fall short when faced with new, unknown threats. New threats may not have a recognized signature, allowing them to slip past the IDS undetected.
- Anomaly-Based Detection: Anomaly-based detection is more like a sniffer dog at the airport. The IDS is trained to recognize what's 'normal' and then flags anything that deviates from this baseline. This ability makes it well-suited to detecting zero-day attacks and other unknown threats. However, it also has a higher chance of false positives, as it might mistake unusual but benign activities as threats.
How does intrusion detection improve network security?
Beyond their immediate role of detecting intrusions, IDS systems offer additional benefits including:
- Ensuring Compliance: An IDS can monitor policy violations, helping enforce your organization's IT security procedures.
- Incidence Response Planning: By analyzing IDS logs, your organization can gain insights into the nature of attacks and establish protocols for similar future incidents.
- Computer Forensics: IDS logs can also be invaluable for forensic investigations, helping you understand the nature of attacks and even potentially identify the culprits.
- Threat Deterrence: Lastly, the mere presence of an IDS can have a deterrent effect. Just as a burglar is less likely to target a house with visible security measures, so too are potential cyber threats likely to think before attacking a network protected by IDS.
What are the limitations of Intrusion Detection Systems (IDS) ?
Despite their advantages IDS systems are not without their limitations. They can sometimes produce false positives, wrongly flag innocent activities as threats, and false negatives where they miss actual threats. Admittedly, these systems require continuous monitoring and regular updates. Combining other security measures alongside IDS such as firewall, antivirus, and network access control can help ensure a more resilient defense against emerging threats.