Survey on Mitigation of DOS and DDOS Attacks in the Presence of Clock drift

Distributed Denial of Service (DDoS) Attacks which can be so powerful that they can easily deplete the computing resources or bandwidth of the potential targets. DDoS attacks can be accosted in two levels: application-level and network-level. The weak point in network-based application is that the communication port is commonly open .This allows attackers to possibly launch Denial of Service (Dos) Attacks. Solutions to this problem are, we use port hopping technique to support many clients without the need of group synchronization in the presence of clock drift. Furthermore we use HOPERAA algorithm and BIGWHEEL algorithm to overcome distributed denial of service attacks.