In this paper, the authors present a treatise about cloud computing security risk and attack, they explained the definition of cloud computing and the P2P network in order to understand the infrastructure and how denial of service attacks consumes and confuses the network infrastructure, the two type of Denial of Service attack (DoS) and DDoS aimed to flood the network storage and to exhaust the network resource. Among the available solutions is SSL certificates but they found It’s not enough to solve and to prevent DDoS/DoS attacks, that due to the existence of SSL handshake attack.