Cyber security is a key aspect of Cloud Computing. Generally data transmission between client devices and cloud is encrypted. However one weak link in the cloud security is the authentication based only on the passwords. In two factor authentication this issue is overcome by using a secondary authentication mechanism in addition to the traditional password authentication, hence the name “Two factor” authentication. The second factor could be a randomly generated number such as the “RSA token” , mobile app , text message etc. By having two methods to authenticate the user who access the cloud computing resource greatly enhances the security .