Blockchain-based verifiable multi-keyword searchable encryption scheme with de-duplication support

Abstract

Searchable encryption technologies aim to retrieve data stored in ciphertext on cloud servers. However, the imperceptible flaws of cloud servers, such as data corruption and data duplication, are prone to trigger concerns of data owners about economic damage and privacy disclosure in the era of the digital economy. Moreover, single-keyword searchable encryption fails to cater to the fine-grained and diversified search demand in practical settings. Additionally, the revolutionary blockchain technology is propelling the evolution of trade fairness. Hence, we proposed a fine-grained multi-keyword searchable encryption scheme based on blockchain under the Modify Decisional Diffie-Hellman (MDDH) assumption. Specifically, ameliorated ciphertext-policy attribute-based encryption is employed to realize fine-grained access and attribute revocation, and data label technology is adopted to achieve de-duplication. Finally, the security analysis and experimental results show that our scheme achieves desired practical security and performance goals.