Design and Development of Proactive Models for Mitigating Denial-of-Service and Distributed Denial-of-Service Attacks

Denial-of-Service (DoS) attacks, orchestrated by a single host or multiple hosts in a coordinated manner, have become an increasingly frequent disturbance in today's Internet. Generally, attackers launch Distributed Denial-of-Service (DDoS) attacks by directing a massive number of attack sources to send useless traffic to the victim. The victim's services are disrupted when its host or network resources are occupied by the attack traffic. The threat of DDoS attacks has become even more severe as attackers can compromise a huge number of computers using vulnerabilities in popular operating systems. This paper deals with proactive models for mitigating DoS and DDoS attacks. In the first part of our investigation, we develop and evaluate two defense models for DoS and DDoS attacks: the Secure Overlay Services (SOS) Model and the Server Hopping Model using distributed firewalls. Each of these models provide defense in a different part of the network, and has different resource requirements. In the second part of our investigation, we assess the effectiveness of our defense models for different types of DoS and DDoS attacks. Key words