Research on Blockchain-Oriented Attribute-Based Searchable Encryption Scheme

With the development of the digital era, data security has become a focal concern. How to improve data retrieval efficiency while ensuring data security has emerged as a new challenge. To address this issue, this paper combines blockchain and cryptographic to propose a blockchain-oriented attribute-based searchable encryption scheme. The scheme chooses a ciphertext-policy attribute-based encryption algorithm to encrypt files, and an attribute-based searchable encryption algorithm to encrypt the inverted index constructed from keywords and file identifiers. File ciphertexts are stored on the cloud server, while index ciphertexts are recorded on the blockchain. Data users generate search trapdoors from their own attributes and query keywords. Smart contracts execute the on-chain search and return matching results, after which users download and decrypt the files from the cloud. Security analysis shows that, in the random oracle model, the scheme achieves both indistinguishability and non-tamperability of keyword ciphertexts. Performance evaluation and system simulation results indicate that, while providing fine-grained access control and privacy protection, the scheme maintains low on-chain overhead and high search efficiency, making it a secure and efficient solution.