Cloud computing is a promise computing technology where all the services are provided via Internet. Recent years have seen increasing attractiveness of storing and managing personal data on the cloud. Preserving confidentiality of personal data while offering efficient functionalities thus becomes an important and pressing research issue. Users know the demand for privacy of information of enterprise has increased tremendously. For this, technologies such as data encryption methods are used. However a critical problem arises when there is a need of computation on encrypted data where privacy is established.