The Study Of The Network Database System Security

The study of security is a systemic project which relating to many aspects of content. It is not perfect to merely focusing on the datebase system when study the NDS (network database security). In this paper , information of former investigations were collected and summarized and some exigent security questions are discussed and solved .The security mechanism and the safety frame are presented to enhancing the NDS by the mechanism. Given no replacing the operating system and the database system, and only discuss the approach to strengthen the NDS, it can be considered that: to enhance the NDS ,both the security of the data storage and that of the data transfer on the internet must be deal with (consider that the storage include all the write and read). In detail, the storage security is split into two aspects : the visit to the data files from the DBMS and the visit to the data files from the operating system caused by other programs ;we discuss the transfer security mainly from local computer.For the operating system aspect , filtrating the visit from other program by a files operation filter is realized , the program run at the operating system kernel model . Thus, the popedom of operating the data files is only given to the DBMS, without permission other programs can never read or write the given files, so, the insecurity from out of the database system and the operating system are refused.From the transfer aspect, the intermediate NDIS driver is used to inspect and filtrate the received packets and the sending packets. Because of the intermediate NDIS diver run at kernel model, it has many security excellence: it is not so easy to be bypassed by application programs, here all kinds packets can be received, such as ICMP packets, ARP/RARP packets, etc. So, sure, inspect and filtrate at the intermediate NDIS layer has more safety.In this paper, the security of the application design and the application program of database are introduced, which can never be ignored. And much knowledge of writing soft driver, how to set the security option of the Windows operating system and of the MS SQL Server database system and of the network are introduced too. also , the knowledge of security grade and the grade of the widely used commercial database systems are introduced.