CIM: CP-ABE-based identity management framework for collaborative edge storage

Collaborative edge storage (CES) can provide high-quality data sharing for end users through the collaborative use of edge storage resources. However, due to the lack of trust between different edge storage servers, satisfying data authenticity, storage reliability, and identity privacy protection simultaneously become the main research challenge in the field of CES. While the emerging blockchain-based collaborative storage solutions (BBCES) can solve the problems of data authenticity and storage reliability, the transparency of blockchain makes privacy become the main issue. In this paper, we propose a CP-ABE-based identity management framework (CIM), which can effectively protect the identity information of edge entities in the BBCES. On CIM, we design a CP-ABE scheme to protect the identity privacy of edge entities by encrypting classified identity information. The encrypted identity information of a new joining entity will be recorded in the blockchain. When edge entities participate in CES, the identification number of their encrypted identity information will be recorded in the blockchain. Besides, via the tracing algorithm, the system entity can get the authorized identity information of these edge entities participating in a specific CES, which can realize identity traceability while protecting identity privacy. Further, theoretical analysis and extensive experiments have demonstrated the effectiveness and performance of this scheme in the identity privacy protection of CES.