Fast Query Over Encrypted Character Data in Database.

Cryptographic support is an important dimension of securing sensitive data in databases. But this usually implies that one have to sacrifice performance for security. In this paper, we describe an novel cryptographic schemes for the problem of searching on encrypted character data and provide analysis of security for the resulting cryptographic systems.When the character data are stored in the form of cipher, we store not only the encrypted character data, but also characteristic values of character data as an additional field in database.When querying the encrypted character data,we apply the principle of two-phase query. Firstly, it implements a coarse query over encrypted data in order to filter part records not related to querying conditions. Secondly, it decrypts the rest records and implements a refined query over them. Results of a set of experiments validate the functionality and usability of this approach. [ABSTRACT FROM AUTHOR]