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.