BDAE: A Blockchain-Based and Decentralized Attribute-Based Encryption Scheme for Secure Data Sharing.

Ciphertext-policy attribute-based encryption (CP-ABE) is widely employed for secure data sharing and access control. However, its dependence on a single authority introduces security and performance challenges. Despite the existence of multi-authority CPABE approaches, persistent issues such as single points of failure and high computation cost on the user side remain. This study proposes a novel solution named blockchain-based and decentralized attribute-based encryption (BDAE) for data sharing. BDAE enhances traditional scheme by integrating blockchain and distributed key generation technology. The scheme employs an (n, t) threshold secret sharing algorithm, coupled with the Pedersen verifiable secret sharing method, for attribute key generation. This combination ensures key credibility, facilitates joint attribute management, and addresses single bottleneck and key verification issues. Integrated into a blockchain system, the scheme utilizes smart contracts for fine-grained access control and outsourced computing. Blockchain's decentralization and access logs make data sharing tamper-resistant and auditable. Moreover, simulation comparisons demonstrate that the scheme effectively reduces decryption overhead on the user side, meeting practical application requirements. [ABSTRACT FROM AUTHOR]