Application Layer DDOS Attack Detection and Defense Methods

Nowadays in the cyberworld, the Internet has dramatically revolutionized many different fields and different public services globally. Due to any reason, unavailability of these services leads to enormous cost implications and it even affects society. Adistributed denial of service (DDOS) attack is amajor cybersecurity threat designed to deny services to legitimate users. These days, application-layer distributed denial of service attacks are the main threat on web servers. This paper addressed application layer DDOS attacks typical architecture, common detection mechanisms and defense methods. Numerous Application layer DDOS attack detection techniques have been developed, these can generally be described as detection methods based on the signature, anomalies and hybrids. In anomaly detection, we discussed statistical and machine learning-based methods by researchers. We classified defense mechanisms as defense methods and a combination of detection and defense methods.