Security and privacy are very important issues in cloud computing. In existing system access control in clouds are centralized in nature. The scheme uses a symmetric key approach and does not support authentication. Symmetric key algorithm uses same key for both encryption and decryption. The authors take a centralized approach where a single Key Distribution Center (KDC) distributes secret keys and attributes to all users. A new decentralized access control scheme for secure data storage in clouds that supports anonymous authentication. The validity of the user who stores the data is also verified.