A Privacy-Preserving Data Sharing System with Decentralized Attribute-based Encryption Scheme

Li Kang ； Leyou Zhang

《International Journal of Network Security》 22卷5期 (2020/09) Pp. 815-827

https://doi.org/10.6633/IJNS.202009_22(5).12

摘要

The huge storage space and powerful computing power make cloud servers be the best place for people to store data. However, convenience comes with the risk of data leakage as the cloud servers are not completely reliable. To ensure data confidentiality and user privacy, decentralized attribute-based encryption (ABE) can provide a solution. Nevertheless, most of existing works cannot provide a complete method since there are some vulnerabilities in users' collusion resilience and privacy protection. In this paper, a decentralized ciphertext-policy (CP) ABE scheme is proposed for the secure sharing of data. In the proposed scheme, without requiring any cooperation and knowing users' global identifiers (GID), authorities can issue private keys for users independently through a privacy-preserving key generation protocol. Additionally, this scheme supports policy anonymity. The security of the proposed scheme is reduced to the decisional bilinear Diffie-Hellman (DBDH) assumption. Theoretical analysis and performance evaluations illustrate the efficiency of the scheme.

關鍵字

Cloud Storage ； Data Sharing ； Decentralized CP-ABE ； Privacy-preserving