International Journal of Computer Applications
Storage-as-a-Service (SaaS) offered by Cloud Service Providers (CSPs) enables customers to store and retrieve almost unlimited amount of data by paying fees metered in GB/month. For an increased level of scalability, availability and durability, some customers may want their data to be replicated on multiple servers across multiple data centers. In this paper, the authors propose a Pairing-Based Provable Multi-copy Data Possession (PB-PMDP) scheme, which provides evidence that all outsourced copies are actually stored and remain intact. Moreover, it allows authorized users (i.e., those who have the right to access the owner's file) to seamlessly access the file copies stored by the CSP, and supports public verifiability. The proposed scheme is proved to be secure against colluding servers.