An Efficient Way to Prevent Dos/DDos Attack in the Cloud Environment

In today, the most demanding service over the internet is cloud computing. Over the internet various packets are send and receives. At the time of sending and receiving packets various threats are encountered. One or more threats or attackers are involve in Distributed Denial of Service (DDoS). DDoS come into picture at the time of huge amount of packets are forwarded to a server from many computers. In the cloud computing there is various attacks like DOS (Denial of service) and DDOS (Distributed Denial of service). This paper proposed, attack can be overcome by Transmission Control Protocol (TCP) Mitigation Strategy which uses the SYN Cookie to prevent the attack in the cloud which the server ignores the connection packets when it receive the false or incorrect Acknowledgement (ACK) from the client which requested the connection. Proposed system gives the two layer of security. The server here has rules to be check whether it is a legitimate client or the spoofed one using the first layer of security for hop count filtering mechanism and second layer of security is encoding the sequence number of the SYN packet so that only a legitimate client can decode it. Additionally security is also provided for the data packets using the Message Authentication Code (MAC) and thus client is authenticated.