We are introducing a new decentralized access control procedure which supports anonymous authentication for secure data storage in clouds. With-it the proposed scheme, the cloud verifies the series authenticity before storing data without knowing the user's identity. Our protocol also has the added access control feature in which only legitimate users can decrypt the stored information. Decentralized access control has several properties, such as privilege decentralized, policy definition decentralized, and allows application-defined methods and synchronization specifications, where the user may create another user under the user's subset and grant him unique access to the data by position or designation. Decentralized storage mechanism that is used to retrieve or receive data offers improved user authentication, device cancellation, such as revocation and replay attacks that can be triggered by delayed legitimate network data transmission. We developed a hospital management system where administrators, physicians, patients, labs, nurses are the consumers in the system where administrators have access to the data. For example: doctor can read data from the patient but can't change it so, admin just gives the doctor permission to read it. In this program we use KDC which KGC(key Generation Center) generates and groups. The system's main aim is to provide the data stored in the cloud with better protection and privacy, because the data stored in it is highly sensitive.