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POBRES: Policy-based re-encryption schema for secure resource management in clouds

Security and privacy challenges are the most important obstacles for the advancement of IT-based on-demand services and cloud computing as an emerging technology. To ensure data confidentiality and fine-grained access control in cloud-based environments, stored data and resources needs to be re-encrypted periodically or based on special mechanisms such as revoked user-based or manual re-encryption. Managing the process of re-encryption is a challenging issue that involves many limitations such as time management, resource confidentiality, and level of access. Accordingly, a multi-level re-encryption model based on policy management has been presented in this paper to ensure data security in clouds. The proposed model uses a policy-based ontology to generate, manage and apply re-encryption policies based on the characteristics of resources, sensitivity of data and capabilities of service provider. The results of comprehensive performance and security analysis of proposed model shows this model increases the reliability of re-encryption processes in cloud storages considerably and provides an efficient policy management for re-encryption tasks.