SPACE-EFFICIENT COOPERATIVE METHOD FOR DETECTING DDoS ATTACKS

Abstract

Today, Internet is the prime medium for communication which is used by the number of users across the globe. At the same time, its commercial nature is causing increasing vulnerability to cyber crimes and there has been an enormous increase in the number of DDoS attacks on the Internet over the past decade. Network resources such as network bandwidth, web servers and network switches are mostly the victims of DDoS attacks. Current Internet architecture allows the attacker to spoof the source address of the IP packet by rewriting the packet header. This gives provision to conceal the identity of the source of attack. IP spoofing is the most popular form of Distributed Denial of Service attack. A large number of schemes have been proposed and implemented for the defense against DDoS attacks. Some defend the attack by filtering and dropping packets and some defend the attack by tracing back to the source of attack after experiencing it. Both mechanisms have their own drawbacks. However these schemes require a large amount of space and do not use cooperation. In this dissertation "A. Space-Efficient Cooperative Method for Detecting DDoS Attacks ", we proposed a space-efficient cooperative scheme which produces warning of the DDoS attack at an early stage. It uses a Bloom filter-based detection scheme to generate accurate detection results and- at the same time consumes less space and computational resources. The proposed scheme has been simulated using NS-2 (Network Simulator) on a Linux platform. Various test cases have been designed, for which simulations were performed by varying different parameters. The comparison of results with the existing schemes has overcome with some of the limitations like space, hash collisions etc. iii