Dynamic database filling method based on outlier detection technology and bitmap index

Abstract

The invention provides a dynamic database filling method based on an outlier detection technology and bitmap indexes. The method comprises the following steps that firstly, a filling database is generated, an outlier detection technology is used for selecting a pseudo file meeting conditions to fill a real database, and the corresponding relation between the file and a keyword is represented by a bitmap index; the filling database is dynamically modified according to the updating operation, and if the updating operation is adding and the number of files corresponding to the updated keyword is the largest, other keywords are filled according to the number; otherwise, the filling of the keyword is reduced until the frequency of the keyword is reduced to be the same as that before the updating operation. And if the update operation is deletion, adding the filling of the keyword until the frequency of the keyword is increased to be the same as that before the update operation. The filling method is suitable for a dynamic searchable encryption scheme, data leakage can be prevented, for example, attacks inferred based on keyword frequency can be resisted, and the security of the scheme is improved.

Description

technical field [0001] The invention relates to the technical field of searchable encryption, in particular to a dynamic database filling method based on outlier detection technology and bitmap index. Background technique [0002] With the rapid development of the network and the advent of the era of big data, local storage and computing resources cannot meet people's needs, and cloud storage and computing technologies have developed rapidly. In order to ensure data security, the data is usually encrypted and uploaded to the cloud server. However, performing searches on ciphertext data is very difficult. Therefore, Searchable Encryption (SE, Searchable Encryption) technology is proposed. Early SE solutions were static and did not support dynamic database updates, such as adding or deleting uploaded files, which limited the application of SE solutions. In order to solve this problem, Dynamic Searchable Symmetric Encryption (DSSE, Dynamic Searchable Symmetric Encryption) te...

AI Technical Summary

Problems solved by technology

[0003] However, there is a problem of data leakage in the DSSE scheme. For example, attacks based on keyword frequency inference (such as counting attacks) can easily identify query keywords from access patterns, that is, query results. Database filling technology is a simple and effective solution to the above problems. measures, and is suitable for real large datasets

In recent years, the research focus of filling algorithms is mainly on how to design efficient filling schemes. However, none of the existing filling algorithms are suitable for dynamic databases.

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