Cloud computing has become the latest trend in IT (Information Technology) industry. The term cloud computing refers to an infrastructure, designed with both hardware and system software, where data storage and computing uses data centres instead of personal computers, and the applications are distributed as services over the internet. It can be compared with a large pool which is easily accessible and contains vast amount of virtualized resources which can by vigorously reconfigured for optimum scale employment by adjusting variable load. Started only as a basic business concept, cloud computing has become the fastest growing trend in the IT industry in a few years. With more and more business organizations and individuals, cloud computing has grown large, and with that security has become a major issue in the field. The risks of data breaches and vulnerability pose a threat in present cloud environment which has not only technological but also significant social impact