International Association of Computer Science and Information Technology(IACSIT)
An increasing number of applications have been proposed and discussed on the cloud computing environment because it can bring many benefits like reducing the cost of maintaining data centers in an enterprise, low data management cost and retrieval of data whenever the user want, etc. As more and more sensitive information and personal data are centralized into the cloud servers, how to protect data privacy and combat the unauthorized accesses is an important issue in the cloud computing environment since the outsourcing-service server may not be fully trusted. One method to alleviate the security worries is storing data in the encrypted form. The drawback of the encrypted data is the limitation of usability.