Design of Privacy-Preserving Cloud Storage Framework

Privacy security is a key issue for cloud storage. To solve this problem, the paper proposes a privacy-preserving cloud storage framework, which includes the design of data organization structure, the generation and management of keys, the treatment of change of users´ access right and dynamic operations of data, and the interaction between participants. We design an interactive protocol and an extirpation-based key derivation algorithm, which are combined with lazy revocation, multi-tree structure and symmetric encryption to form a privacy-preserving, efficient framework for cloud storage. A system is realized which is based on the framework. The paper analyzes the effectiveness of extirpation-based key derivation algorithm, the overhead of the system and the privacy security of the framework. Finally, we summarize our work and introduce our future research directions.