Secure Data Sharing for Cloud-Based Services in Hierarchical Multi-group Scenario

摘要

This paper proposes a cloud-based framework to enable secure data sharing among multiple groups of people organized in a hierarchy. The framework supports restrictive communication scenarios where one can define a communication policy by specifying "who can communicate to whom, " in order to respect the hierarchical structure. We improve the tree-based group key management scheme reducing both time and space complexities and we extend it to the case of intra- and inter-group secure communications. The key distribution process does not involve any semi-trusted third party and hence improves the robustness. Unlike existing techniques, our proposal fits very closely to the real-world scenarios where multiple groups exist in hierarchical order, for example in any organizations or institutes.