This paper presents a model driven approach to define then coordinate the execution of protocols for secure outsourcing of computation of large datasets in cloud computing environments. First we present our Outsourcing Protocol Definition Language (OPDL) used to define a machine-processable protocols in an abstract and declarative way while leaving the implementation details to the underlying runtime components. The proposed language aims to simplify the design of these protocols while allowing their verification and the generation of cloud services composition to coordinate the protocol execution. We evaluated the expressiveness of OPDL by using it to define a set of representative secure outsourcing protocols from the literature.