What is Intrusion Detection System (IDS)? Types & Techniques

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HIDS host-based intrusion detection system runs on independent devices, i.e., a host on the network monitors the incoming and outgoing packets and alerts the administrator about malicious activity. It takes a snapshot of the existing system files to identify the abnormalities. If there are any discrepancies among the file sent or if anything got deleted, an alert is sent to the administrator for further investigations. 

2. Protocol-Based Intrusion Detection System (PIDS):

PIDS, a Protocol-based IDS, is a system or agent that resides consistently at the front end of the server to control and interpret the protocol between the user and the server. PIDS is for securing the web server by monitoring the HTTPS protocol stream. A typical use of PIDS is at the front end of the web server, keeping a check on the HTTP or HTTPS stream.  

3. Application Protocol-Based Intrusion Detection System (APIDS):

An application-based intrusion detection system is a system that stays within a group of servers. It identifies the intrusions by monitoring and interpreting the communication on application-specific protocols. 

APIDS uses machine language to establish the baseline of the expected system behavior in terms of bandwidth, parts, protocol, and device usage.

4. Hybrid Intrusion Detection System:

MDPI

A hybrid intrusion detection system results from two or more approaches to the IDS. in this, the host agent or the system data is combined with the network information to develop a complete view of network systems. This system is quite effective in comparison to other IDS.  

Detection Method of IDS Deployment

Any IDS uses different methods for detecting malicious network traffic. Some of them are:  

1. Signature Detection:

Signature-based intrusion detection systems use fingerprints of known threats to keep a check on them. Once the malicious traffic or packets are detected, the IDS generates a signature to scan the incoming traffic to detect known malicious patterns. The signature-based IDS can detect the attacks whose patterns are already present in the system but are unable to detect new or unknown malicious or attack network traffic.  

2. Anomaly Detection:

The anomaly-based intrusion detection system was introduced to detect unknown malicious attacks as new attack methods are developed quickly. This detection method uses machine learning to create a trustful activity model, and anything that comes is compared with that model to detect malicious traffic or patterns. The machine learning-based method has better-generalized property as compared to the signature-based IDS and are trained with the IDS application and hardware configurations.   

3. Hybrid Detection:

This IDS uses both signature-based as well as anomaly-based detection system and enable it to detect potential threats with a minimum error rate.   

Intrusion Detection System Evasion Techniques  

Intrusion Detection Systems are important for protecting networks, but attackers use clever tricks to avoid detection. Knowing these tricks can help improve IDS performance. 

• Fragmentation: This method splits malicious data into small packets that slip through unnoticed.   
• Obfuscation: This technique changes attack patterns to avoid detection.   
• Protocol violations: This tactic sends faulty packets that confuse the IDS.   
• Rate-based evasion: It involves slow attacks to stay under the IDS radar.   
• Encryption hides malicious data, making it hard for IDS to inspect.   

To fight these tactics, IDS must use deep packet inspection, update their signatures often, and employ smart detection methods to catch these sneaky attacks.

How To Select An IDS Solution?

Once you know what IDS is and its detection, you need to follow these steps to select an IDS solution: 

Step 1: Identify The Baseline: To ensure that your IDS works appropriately, set a baseline so you would know what's coming on your network. Keep in mind that every network carries additional traffic, and defining a pre-set initial baseline help prevent false negatives. An intrusion detection system in network security will keep your network protected from firewalls.  To ensure that your IDS works appropriately, set up a baseline so that you would know what's coming on your network. Keep in mind that every network carries different traffic, and defining a pre-set initial baseline help prevent false negatives. An intrusion detection system in network security will keep your network protected from firewalls.

Step 2: Define The Deployment: Always deploy the distributed intrusion detection system at the highest point to not overwhelm the system with data. Place it at the edge, behind the firewall, or install multiple IDSes if you are dealing with a lot of traffic. 

Step 3: Test The IDS: Test the system to ensure it detects the potential threats and responds to them properly. Use test datasets or have security professionals do a pen test.

Advantages Of Intrusion Detection System (IDS)

Apart from raising the alarms, the intrusion detection system software also helps in configuring rules, policies, and respective actions to be taken. 

Below are the benefits of using an IDS: 

1. It keeps a check on the routers, firewalls, key servers, and files and uses its database to raise the alarm and send notifications. 
2. Offer centralized management for the correlation of the attack. 
3. Act as an additional layer of protection for the company. 
4. It analyzes different attacks, identifies their patterns, and helps the administrator to organize and implement effective control. 
5. Provide system administrators the ability to quantify the attack. 
6. An IDS in cyber security help detects cybersecurity problems. 

Disadvantages Of Intrusion Detection System (IDS)

There are four key challenges that businesses face when managing IDS systems: 

1. Ensuring Effective Deployment: To ensure a high level of visibility, companies must ensure that their wireless intrusion detection system is optimized and installed correctly. While deploying IDS can be tricky, and if not done properly, it may create vulnerabilities for critical assets.  
2. Understanding and Investigating Alerts: IDS alerts give very little information, which, sometimes, is hard to investigate. You may lag with information like what caused the attack or what further actions are required to oppose a threat. Also, investigating the IDS alerts can be time and resource-intensive, which may require additional information to identify the seriousness of the attack. 
3. Managing a High Volume Of Alerts: Since there is the vast majority of attacks are generated by intrusion detection, it may put the burden on internal teams to identify each one of them. Sometimes, these system alerts are false positives, which are hard to screen.  Also, some IDS come pre-loaded with some defined alert signatures that are insufficient for many organizations. 
4. Knowing How To Tackle Threats: A common issue that organizations face is the lack of appropriate incident response capability. Identifying a problem is half a thing; knowing how to respond appropriately is a challenging and critical thing. An effective incident response needs an expert who knows how to remediate threats and what procedures are required to address the issue. Sometimes a home intrusion detection system gives false alarms, so keep a check on the type of threats and how you need to handle them. 

The cyber security team needs to be updated with the latest progress and update in IDS and key domains of cyber security. Courses such as CEH training are very useful for keeping pace with learning.  

IDS Vs Firewall 

Installing an intrusion Detection System project and a firewall offers cybersecurity solutions deployed to protect the network or its endpoint. (get into the basics to advance with the help of the best IT Security certifications and know how these IDS help in cybersecurity) However, both serve different purposes.

An IDS is a passive monitoring device that helps detect threats and generate alerts. It enables SOC (security operation center) analysts or incident responders to detect and respond to the threat. An IDS provides no protection to the endpoint.

On the other hand, a firewall is an active protective device and is more like an Intrusion Prevention System (IPS). It performs analysis of the metadata of the network packets and helps block/allow the traffic based on some pre-set rules. This creates a boundary on which some types of traffic or protocols cannot pass.

IDS and IPS 

Understanding the difference between IDS and IPS is important for designing concrete security architectures that can effectively detect and prevent cyber threats. 

Aspect	IDS (Intrusion Detection System)	IPS (Intrusion Prevention System)
1. Functionality	Monitors network traffic and generates alerts for suspicious activities.	Monitors network traffic and takes proactive actions (such as blocking) against suspicious activities.
2. Action	Passive – only alerts about potential threats.	Active – prevents and mitigates threats in real-time.
3. Placement	Positioned within the network to monitor traffic and detect anomalies.	Positioned in-line within the network path to intercept and block threats.
4. Response Time	Delays in response as it requires manual intervention to address threats.	Immediate response to threats, reducing the risk of damage.
5. False Positives	Higher rate of false positives due to its monitoring nature.	Lower rate of false positives due to real-time prevention mechanisms.

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Conclusion

Keeping in mind the challenges of ongoing system monitoring, maintenance, and alert investigation, many organizations wish to consider having secure network-based intrusion detection systems. A managed Intrusion Detection System (IDS) service avoids recruiting a dedicated security person and sometimes includes the requisite technology, minimizing the need to maintain capital expenditure.