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A Petri Net Model for Secure and Fault-Tolerant Cloud-Based Information Storage

Cloud computing provides a promising opportunity for both small and large organizations to transition from traditional data centers to cloud services, where the organizations can be more concerned with their applications, services, and data rather than the underlying network infrastructures and their associated cost. There are major concerns, however, with data security, reliability, and availability in the cloud. In this paper, we address these concerns by proposing a novel security mechanism for secure and fault-tolerant cloud-based information storage. We present a formal model of the security mechanism using colored Petri nets (CPN). The model utilizes multiple cloud service providers as a cloud cluster for information storage, and a service directory for management of the cloud clusters including service query, key management, and cluster restoration. Our approach not only supports maintaining the confidentiality of the stored data, but also ensures that the failure or compromise of an individual cloud provider in a cloud cluster will not result in a compromise of the overall data set. Keywords-Cloud computing; information storage; data security; fault tolerant; colored Petri nets; formal modeling and verification.