A novel verifiable chinese multi-keyword fuzzy rank searchable encryption scheme in cloud environments

As an important cryptographic primitive, searchable encryption (SE) plays a crucial role in performing keyword searching on encrypted texts. However, in order to realize fuzzy keyword search, most fuzzy search encryption schemes utilize wildcards and gram technology to construct fuzzy sets, which consumes a lot of storage and computational resources. Therefore, in this paper, we propose a new verifiable Chinese multi-keyword fuzzy rank searchable encryption (VCMKFRSE) scheme. Firstly, we take advantage of the Yongzi Ba method to convert Chinese keywords into stroke strings, and employ chinese keywords vector generation algorithm to convert the stroke string into a keyword vector. Secondly, we utilize inverted index tables to establish the relationship between keywords and documents. In particular, the relevance score between keywords and documents is calculated by using the three-factor algorithm. Also, we adopt the MinHash function to construct a fuzzy index table for each keyword vector. Thirdly, in order to realize the authentication of search results and avoid receiving useless search results, we build an authentication tag table by using an authentication tag generation function. Afterwards, we apply probabilistic trapdoors to resist distinguishability attacks. At last, our scheme achieves IND-CCA secure and is more efficient comparing with the state of the art. Overall, our proposal achieves fuzzy multi-keyword search and more accurate search result ranking, while ensuring data security and higher efficiency.