The usage of cloud computing has seen drastic growth in many organizations in the world. Cloud computing is use of computer resources that are delivered as a service over a network. Cloud computing provides many advantages such as sharing resources, low cost, improved accessibility. Ensuring the security in cloud computing environment is an issue of concern, because users mostly store sensitive information with the service providers. Dealing with single cloud involves the risk of accessibility failure and intervention of third party. Due to this a step towards inter-clouds or multi-clouds or clouds-of-clouds has born.