The Technology For Character Data Encryption In The Relational Database

With the development of Internet and database technology, databasesecurity is becoming more important and complex. The original data in thedatabase is readable, and it is necessary that the important and sensitive data isencrypted, and this is the last safeguard before real threat. But encryptionaffects the performance of the system deeply so that the practice queryapplications for the large database hardly achieve. A safe and efficiency highlyalgorithm must be found to meet the expectation of practice application.Order preserving encryption for numeric data is analyzed thoroughly. Sofrom the various viewpoints two improvement methods for character data areproposed: OPES+ and FMEM (Fuzzy Match Encryption Method).Firstly, from the viewpoint of simple operation, OPES+ is put forward.The encryption principle, process, key technology and frame are developed.The security and overhead for time and space are analyzed theoretically.Secondly, from the viewpoint of practicability, FMEM is put forward.Primary idea and Encryption process are described. The principle ofconventional query operation is instanced. The principle and efficiency of thekey technology and the security of the algorithm are analyzed theoretically. Aseparate key management method preventing cheat is proposed.Finally, the experiments are conducted to prove the algorithms fromvarious aspects of percentile exposure, incremental updatability and overheadof time and space. Query quality of two methods is compared with conven-tional ways, and it offers direction and experience for more research.