Security ensured multicopy data management framework for cloud service providers

The Cloud Service Providers (CSP) is deployed to support data storage and computational resources for the users. Data owners share the data values under the Cloud Service Providers. Authorized users access the data from the CSPs. Increasingly more and more organizations are opting for outsourcing data to remote cloud service providers (CSPs). Customers can rent the CSPs storage infrastructure to store and retrieve almost unlimited amount of data by paying fees metered in gigabyte/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. The more copies the CSP is asked to store, the more fees the customers are charged. Therefore, customers need to have a strong guarantee that the CSP is storing all data copies that are agreed upon in the service contract and all these copies are consistent with the most recent modifications issued by the customers. The cloud data sharing system is constructed with a map-based provable multi copy dynamic data possession (MB-PMDDP) scheme. The MB-PMDDP scheme achieves the following benefits. 1) it provides an evidence to the customers that the CSP is not cheating by storing fewer copies; 2) it supports outsourcing of dynamic data, i.e., it supports block-level operations, such as block modification, insertion, deletion and append and 3) it allows authorized users to seamlessly access the file copies stored by the CSP. The system verifies the data storage with multiple data copy model and data distribution operations.