BMTAC: a decentralized, auditable, time-limited, multi-authority attribute access control scheme in blockchain environment
Zhigang Xu, Sun Qing, Hongmu Han, Xinhua Dong, Zhongzhen Yan, Zhiqiang Zheng, Wenlong Tian · 2022
Ciphertext Policy Attribute-Based Encryption (CPABE) technology is often used in data sharing platforms. Most of the existing CP-ABE schemes do not consider time-sensitive data, which may easily lead to some unpublished information being leaked in advance. Therefore, combining time and attributes, this paper proposes a decentralized, auditable, time-limited multi-authority attribute access control scheme (BMTAC) in a blockchain environment. It can solve the single point of failure problem, the trust problem, and the cross-domain problem in a multi-authority scheme. This scheme combines the Fabric Network to manage permissions of different organizations jointly. Different organizations’ CA(Certificate Authority) issue digital certificates for entities and generate time tokens for attributes. Smart contracts collect attribute and time tokens to encrypt and decrypt ciphertext data and reduce client communication and computing costs. Furthermore, the comparative experiments show that the BMTAC scheme with the added attribute time limit has a good time cost in encryption and decryption, effectively reducing the computing overhead of users. Finally, the analysis of the security model proves the security of the scheme.