关键词: 可搜索加密, 多关键词, 密文排序, 区块链, 索引树

Abstract: To address the issue of untrusted cloud storage servers, a blockchain-based searchable encryption scheme is proposed. The scheme utilizes a balanced binary tree as the index tree to achieve sublinear search efficiency. It employs a vector space model to reduce text complexity. The sorting of search results for multiple keywords is achieved through the TF-IDF (Term Frequency-Inverse Document Frequency) weighting and statistical algorithm. By employing a separate index tree for newly added files and maintaining a revocation list for deleted data, the scheme enables dynamic updates in the blockchain-based searchable encryption solution. Through leakage function, it is proven that the scheme is secure against adaptive chosen keyword attacks. Performance testing analysis demonstrates that the scheme realizes a dynamic updateable encrypted sorting and retrieval solution for keywords on the blockchain.

Key words: searchable encryption, multiple keywords, ciphertext sorting, blockchain, index tree