In this paper, the authors propose a new access control scheme for providing security to the data stored in clouds. The other access control schemes which are already designed are centralized i.e. having a single KDC (Key Distribution Centre) nature. Their access control scheme is decentralized that supports anonymous authentication. In their proposed system "Before storing data and without knowing users identity the cloud verifies the authenticity of the series". Access control is another feature which allows only valid users to decrypt the stored information from cloud. Their proposal successfully prevents replay attacks and also supports creation, modification and reading of data stored in the cloud.