Abstract: Cloud computing is an emerging paradigm which has become today’s hottest research area due to its ability to reduce the costs associated with computing. In today’s era, it is most interesting and enticing technology which is offering the services to its users on demand over the internet. Since Cloud Computing stores the data and disseminated resources in the open environment, security has become the main obstacle which is hampering the deployment of Cloud environments. Even though the Cloud Computing is promising and efficient, there are many challenges for data security as there is no vicinity of the data for the Cloud user. To ensure the security of data, we proposed a method by implementing RSA algorithm. After implementing RSA Algorithm, we have also analyzed the performance of our algorithm based on three parameters namely Time Complexity, Space Complexity and Throughput. In our proposed work, we are using RSA algorithm to encrypt the data to provide security so that only the concerned user can access it. By securing the data, we are not allowing unauthorized access to it. User data is encrypted first and then it is stored in the Cloud. When required user places a request for the data to the Cloud provider, Cloud provider authenticates the user and delivers the data.

Keywords: Cloud Computing, Data Security, RSA algorithm, Encryption, Decryption, Time complexity, Space complexity, Throughput.