Abstract: A data distributor has given sensitive data to a set of supposedly trusted agents (third parties). Some of the data are leaked and found in an unauthorized place (e.g., on the web or somebody’s laptop). We propose data allocation strategies that improve the probability of identifying leakages. In Image and Video we can apply watermarking for detecting guilty agent. All the data will be stored on the cloud so Reliable Re-encryption in unreliable clouds technique is used. In this data owner store encrypted data in the cloud, and issue decryption keys to authorized users. When a user is revoked, the data owner will issue re-encryption commands to the cloud to re-encrypt the data, to prevent the revoked user from decrypting the data, and to generate new decryption keys to valid users, so that they can continue to access the data. In this project a time based re-encryption scheme is used for cloud servers to automatically re-encrypt data based on their internal clocks.