The terms IDS (intrusion detection system) and IPS (intrusion prevention system) often get used interchangeably in articles about data security in the cloud. This can lead to some confusion about how each of these systems work.
While closely related, there is a world of difference between how intrusion prevention and detection systems help businesses protect their data.
Passive Monitoring vs. Active Protection
Both intrusion detection and prevention systems monitor activity on a computing environment such as a cloud-based virtual machine (VM) for signs of intrusion by a hacker or other malicious actor. The major difference is in what happens after an intrusion is detected.
IDS measures will log a potential intrusion event and rely on a system administrator to review and resolve the detected threat. The detection system will take no further action on its own to remediate the intrusion.
This creates a delay as the solution has to wait on the admin to notice the event and take action. IDS Solutions are much more favorable when potential security events are constantly being viewed by security professionals. Most companies don't have the resources to afford a team watching events 24/7.
In the minutes—or even hours—that it takes for an admin to spot the event and take action, hackers could do untold damage to a company’s data environment or compromise sensitive customer information.
By contrast, when an intrusion prevention system detects an intrusion event, the system will immediately start to take measures to remediate the event and generate an event report. This allows IPSs to remediate intrusion attempts in a fraction of the time of using an IDS alone.
Typical prevention measures taken by an IPS system include:
- Dropping malicious traffic packets
- Blocking traffic from the IP address that sent the packets
- Resetting network connections
This active protection model is what separate IPS from IDS on a practical level. There are many more differences under the hood between these two systems, but the ability of IPS to actively counter intrusion attempts in real time is the most important differentiator for most businesses.
IPS vs. Firewalls
IPS and firewalls share some similarities in that they’re designed to thwart malicious traffic on a network. Both solutions sit in-line with your network traffic to monitor information packets as they pass through.
The major difference between these solutions is in how they analyze traffic.
Most firewalls check for the behavior and logic of a data packet—where it’s from and where it’s going, plus some light integrity inspection. Traffic headed from or to untrusted sources are dropped quickly and efficiently.
IPS solutions can use much more sophisticated threat detection models. These solutions often employ contextual, statistical information about data access to identify unusual actions and block access. In addition to this statistical anomaly detection, IPS solutions can use signature-based detection that is either exploit or vulnerability-facing.
This greater range of detection models, and the ability to analyze all traffic on the network rather than just traffic crossing the perimeter helps to make IPS a powerful tool for maintaining network security.
However, most security solutions will use both IPSs and firewalls to provide security for a business’ network. This enhances the overall protection of the network better than using one solution or the other alone.
When protecting mission-critical data and applications, using multiple layers of security to minimize exposure is a must. No single solution will cover all cybersecurity needs. So, while IPS does measure up favorably as a security solution, it shouldn’t be the only measure your company uses.