A Framework for Nonrepudiatable and Scalable Cross-Enterprise Workflow Management Systems in the Cloud

Cloud computing is gaining tremendous momentum in both academia and industry, with more and more people and enterprises migrating their data and applications into the cloud. Cloud computing provides a new computing model with elastic scaling, a resource pool of unprecedented size, and the on-demand resource provisioning mechanism, which bring numerous challenges in implementing workflow management systems (WfMSs) in the cloud. Establishing scalable and cross-enterprise WfMSs in the cloud requires the adaptation and extension of existing concepts for process management. This paper presents a framework for how cross-enterprise processes can be implemented, secured, controlled, and scaled. We also explain why existing engine-based centralized and distributed WfMSs cannot guarantee the no repudiation requirement. The proposed framework is a document-routing system that implements major required security features such as authentication, confidentiality, data integrity, and nonrepudiation in the cloud computing environment. Its security framework is built by applying element-wise encryption and a cascade-based method of embedding digital signatures. The implementation and experimental results demonstrate the feasibility of the proposed framework.