Abstract: In order to effectively reduce the possibility of data leakage in private database and further improve data security, an adaptive encryption method for private database based on branch obfuscation algorithm is designed in this paper. On the basis of collecting the request contents of the application program to the database, the characteristics of the data in the privacy database are classified by using the branch obfuscation algorithm, and the confusion points in the database are classified by selecting the Naive Bayes classifier, so as to determine the field types of the data in the database. Based on this, data encryption algorithms are selected for different field types. Among them, the sequence-preserving encryption algorithm is used for the numerical data, the equivalent encryption algorithm is used for the equivalent comparison data, and the word segmentation assisted index encryption algorithm is used for the text data. While encrypting numeric, time and character fields, the partial order and searchable properties are preserved. The experimental results show that the proposed method can effectively encrypt the data of different field types in the privacy database, and the encryption requires less time and has high security.

Key words: branch obfuscation algorithm, privacy database, data encryption, field type