Cloud computing is an emerging technology that allows their user to store large amount of data in cloud storage and it can be use whenever required, from anywhere. It provides numerous kinds of services to its users such as software-as-a-service, infrastructure-as-a-service and platform-as-a-service, etc. Storage-as-a-service is one of the services provided by cloud infrastructure in which large amount of data is stored in cloud. As valuable and vital data of enterprises are stored at a remote location on cloud so the authors must be assured that user's data must be safe and be available at any time. In situations like flood, fire, earthquakes or any hardware malfunction or any accidental deletion their data may no longer remain available.