Search encryption method supporting dynamic updating and multi-keyword safe ranking

Abstract

The invention discloses a search encryption method supporting dynamic updating and multi-keyword searching and achieving safe ranking. According to the search encryption method, a red-black tree serves as an index structure, an unencrypted index is generated for a file set, file vectors are stored in leaf nodes, and a union result of child nodes is stored in an internal node. Vectors of all the nodes in the tree are encrypted through an asymmetrical scalar product. During keyword searching, a client side generates a trap door matched with the child nodes of the red-black tree. Calculation is conducted according to the word frequency stored by the leaf nodes, and a top-k file can be returned during searching. When a file is added or canceled, the client side sends a file name and operation, a server returns relevant nodes, and structure updating is achieved in the server. The client side conducts data decrypting and updating and sends decrypted and updated date to the server. Partial updating of the index is achieved through the server. By means of the search encryption method, the dynamic updating purpose of cloud storage data can be achieved, and the user experience can be improved through multi-keyword searching and safe ranking.

Description

technical field [0001] The invention relates to the technical field of network information security, in particular to a searchable encryption method supporting dynamic update and multi-keyword security sorting, which can be used to efficiently retrieve and update encrypted files under cloud storage data. Background technique [0002] With the rapid development of cloud storage technology, many enterprises and individuals will use cloud storage technology to outsource their internal data, saving us a certain amount of equipment resources. Using the powerful data processing capabilities of the cloud server can save a certain amount of computing resources on the client side. However, in order to ensure the confidentiality of the data, the data must be encrypted before the user outsources the data, so it is impossible for the cloud server to obtain valid information from the ciphertext. [0003] However, when a large number of encrypted files are stored on the cloud server, if ...

AI Technical Summary

Problems solved by technology

However, if you want to update a file, you need to download the index to the local and update it all, which is not efficient

Moreover, most of the existing searchable encryption technologies are designed for single keywords, which cannot meet the user's retrieval needs.

And when the server returns the search results, the user hopes to see the top k files that best match the search keywords, and most searchable encryption technologies do not support sorting the search results

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