An authorization model for query execution in the cloud

We present a novel approach for the specification and enforcement of authorizations that enables controlled data sharing collaborative queries in cloud. Data authorities can establish regulating access to their distinguishing three visibility levels (no visibility, encrypted plaintext visibility). Authorizations are enforced accounting information content carried computation ensure no is improperly leaked adjusting on-the-fly. Assignment operations subjects takes into consideration cost operation execution as well encryption/decryption needed make assignment authorized. Our users fully enjoy benefits economic savings competitive open cloud market, while maintaining control over data.