The Research And Realization Of Database Service Provider Model And Its Encryption

From appearance of the Database's technology on 1960s to now, it has been developed and applied rapidly and widely. With the development of computer technology, e-commerce and e-government, especially the Internet, the Database grows a lot of new applied trends. Because of the limitations such as economy, technology etc, many organizations and enterprises have no ability to chase the expensive hardware and software to build their own Database service system as well as they aren't able to overcome the troubles caused by the maintaining data and upgrading software. Therefore, how to build a suit of available and professional database service system in order to resolve their problems. And which mechanism applied by service provider can provide the users to produce data, save data and access data and efficiently protect the data's security. These problems are necessary to be researched.So in this paper, we, utilizing the application service provider model, firstly present the concept of database service provider model. Secondly, we analyze and research the structure of DSP model and build an available DSP model for our further research.In DSP model, the data lying in provider is very important and valuable for the data's owner. So the most important request is the data's privacy. The owners consider the provider is unconfident. And hope anyone, especially the high-privilege DBA(database administrator) of provider, can not steals their data. The other request is the system efficiency. In Internet, the owner's host and the provider's host lie in different place and even different media. So the owners are bound to request the access efficiency. Apparently, this request is very important, too.The encryption plays more and more important roles for the high sensitive and confidential data in database. And the encryption is one of useful ways to protect the data in database from being stolen during saving and transmitting. Therefore, the encryption can be used in DSP model. But the current database encryption has the following faults:Firstly, the SQL cannot directly be operated on the encrypted data. The conventional method is that the queries are be operated on server after the data be unencrypted. But this way not only adds the server's load but also brings some secure problems on server and transmitting path.Secondly, in order to reduce the server's load, the SQL can be operated after the encrypted data are transmitted from server to client and are unencrypted on client. This way can make the network jam so that there is very low efficiency.As a result, on the basis of DSP model structure, we work out and deeply research a kind of new method that can directly research or query on encrypted data so that we can effectively protect the data privacy and guarantee efficiency in DSP. And according to the results of the research, we realize the encryption in DSP. At the same time, these results can be applied not only to database, but also to the saving encrypted data, accessing encrypted data and confidentiality of other fields, such as the secure protection of logs, the secure protection of e-mail, and so on.