Dynamic multi-keyword fuzzy sorting search method and system

Abstract

The invention discloses a dynamic multi-keyword fuzzy sorting search method and system. The system comprises a data user, a data owner and a cloud server. The method is based on a two-stage index structure, a first-stage index is composed of an inverted index and a cross-linked list, keyword fuzzy matching is achieved by combining 2-gram counting sorting, a bloom filter and an LSH (position sensitive hash function), and efficient data updating is achieved by using a new security index constructed by the cross-linked list. The second-level index is based on polynomial user search permission recognition and judgment, and results are sorted by integrating TF-IDF and coordinate matching. In the verification stage, a verification mark is generated for each keyword query to verify the validity of the retrieval result. On the basis of a semi-trusted cloud server, the semantic security of the scheme is realized on the basis of a leakage function. Compared with similar inventions, the fuzzy multi-keyword search scheme provided by the invention has certain advantages, and can meet the sensitive data retrieval requirements of users in a cloud environment.

Description

technical field [0001] The invention belongs to the technical field of information security, and is a dynamic multi-keyword fuzzy sorting search scheme, which can be used for encrypted search and other services when the amount of data is large. Background technique [0002] With the development of cloud computing, more and more data owners outsource data to cloud servers. Cloud servers are often semi-trusted. For this reason, it is necessary to keep data confidential before outsourcing, but direct encryption will destroy the retrievability of data. Therefore, how to ensure data confidentiality while ensuring data retrievability becomes a challenging problem. [0003] Since single-keyword search can only search for one keyword, in actual application scenarios, multi-keyword search is more practical than single-keyword search. Data users are prone to typos when entering keywords. In this case, an exact keyword search fails to return documents of interest to the user. The p...

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Problems solved by technology

[0004] CN104615692B, is a searchable encryption method that supports dynamic update, multi-keyword retrieval and secure sorting. The scheme does not realize the fuzzy search function and lacks practicality in practical applications. This paper proposes a dynamic encryption method based on a two-level index structure. Multi-keyword search scheme, in which the first-level index is composed of inverted index and cross-linked list, combined with Gram counting order, bloom filter and LSH (Location-Sensitive Hashing) to realize the fuzzy matching of keywords

The existence of search efficiency gains in the secondary index structure leads to a contradiction with increased privacy leaks

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