Abstract:

Database encryption is an efficient way to protect data security. Traditional key words query operation cannot be executed directly over encrypted databases. This paper designs an encrypted key words query method based on the bloom filter mechanism. In this method, key words are treated as strings, which are mapped by multiple hash functions and multiple indices are obtained. The bloom array is initialized to 0, and the value 0s of the positions corresponding to the indices of the bloom array are changed to 1s. When searching, the retrieved key words are mapped by the same hash functions and multiple indices are obtained. The search of the encrypted data is realized by judging whether the values of the positions corresponding to the indices of the bloom array are 1s. This paper also gives the introductions of the principle of bloom filter, error analysis and hash function. Experimental results show that the method has high efficiency and practicability.

Key words: bloom filter, encrypted database, hash function