A multi-keyword ciphertext sorting retrieval method based on an alpha cross index tree

Abstract

The invention discloses a multi-keyword ciphertext sorting retrieval method based on an alpha cross index tree. The method comprises enabling a data owner to perform vectorization on a plaintext document through a vector space model; then constructing a binary clustering tree through a binary k-means clustering method, and traversing leaf nodes of the binary clustering tree to obtain a clusteringdocument sequence; constructing the alpha fork index tree from bottom to top on the basis of the clustering document sequence; and finally, outsourcing the encrypted document and the index tree to a cloud server, and sharing a secret key for an authorized user; and enabling the authorized user to send a retrieval request to the cloud server through the retrieval trap door, using the cloud server to return a retrieval result through a greedy depth-first retrieval algorithm, and enabling the authorized user to obtain a plaintext retrieval result after decryption. The protocol flow is simple, thesafety is high, implementation is easy, the retrieval efficiency of multi-keyword ciphertext sorting retrieval is improved, and accurate retrieval is achieved.

Description

technical field [0001] The invention belongs to the field of cloud computing security, and in particular relates to a method for sorting and retrieving multi-keyword ciphertexts based on an α-fork index tree. Background technique [0002] In the environment of big data, how to quickly and effectively retrieve the information needed by users from massive data has become an urgent problem to be solved. With its high-quality computing, storage, and application capabilities, cloud computing technology has become a mainstream model in the IT industry. In the cloud environment, users outsource resource data services to the cloud server to minimize expenditure costs, and protecting user privacy, preventing data from being leaked, and ensuring the efficiency and effectiveness of data obtained from the cloud server have also become people's concerns. focus. [0003] The traditional solution to data leakage is to encrypt the original data, but this will make data utilization face se...

AI Technical Summary

Problems solved by technology

These schemes may be able to return sorted documents more accurately, but with the increase of the document cardinality, the space overhead of the index tree is large, and the pruning effect of the retrieval algorithm will also be reduced, resulting in a decrease in retrieval efficiency. Therefore, it is necessary to propose a Safe, efficient and effective multi-keyword ciphertext sorting retrieval method

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