Research On Character Data Encryption Algorithm And Security

The DB system charges storing and access control of the data information. The primary reasons for the failure are that raw data exist in a readable form. If we encrypt data in the database and then can solve the problems above. Encryption affects the performance of the system deeply so that the practice query applications for the large database hardly achieve. A safe and efficiency highly algorithm must be found to meet the expectation of practice application.Based on the collection and analysis of literatures about database encryption about in recent years, This dissertation researches several key techniques about database encryption at the level of storage, including the architecture and the extended relational schema of the encrypted database, the way of storing and querying the encrypted data. For the encrypted character data, Adopt the encryption outside database and the granularity of field-level. Propose the architecture of query the ciphertext. When character data are stored in the encrypted database, we not only store the encrypted character data, but also turn the character data into characteristic values through using characteristic functions and store characteristic values as additional columns in the encrypted table. Introduce the ways of extracting the characteristic values of the character data. Based on the Pair Coding method, Two method are be constructed One is PC+ method, the other is FS-F-S method base on the Frenquency Sorting Flatten, Scrambling.Finally, the experiments are conducted to prove the algorithms from security, the ablity of query and integrity. Query quality of two algorithms is compared with conventional ways, and it offers direction and experience for more research.