Database Security in DBMS
Database Security includes policies framed to protect data, falling into the hands of unauthorized users. Security also includes the techniques used to ensure that the data elements aren’t changed or deleted by unauthorized persons.
Levels of Security:
Database Management System (DBMS) provides 6 levels of security. These are given below:
1. Network Level Security
2. Operating System-Level Security
3. Database System-Level Security
4. Program Level Security
5. Record Level Security
6. Field Level Security
Network Level Security:
Network Software Level Security is required in the case of a distributed database system. Network Software has a built-in method for login security controls, permitting authorized users to log in and gain access to resources on the network. Another level of security provided by network software is the right security. Right security controls the files, sub-directories and directories. A user or a group of users can access it.
Another level of security is attribute security. Attribute security determines if a particular file can be viewed, shared, renamed, modified or deleted by a user or not. Therefore, even if a user or group of users have the privilege to delete a particular file, but they can’t do so if the attribute of the file doesn’t allow it.
Operating System-Level Security:
Even if you have strong DBMS software, a weak operating system may serve as a means of unauthorized deletion of database files. So, secure OS is most important.
Database System-Level Security:
Some database users may be allowed to access only a portion of the database and denied access to other portions. A user may be permitted to view information but not to modify data. That is, the user can issue SELECT queries but not INSERT, UPDATE or DELETE queries.
Program Level Security:
It debars unauthorized users from using particular programs that may access the database.
Example: A bank account may be allowed to use a program that retrieves details of a customer account, but not a program that modifies the balance account.
Record Level Security:
It debars unauthorized users from accessing or updating certain records, such as records of managers in the EMPLOYEE table.
Field Level Security:
It debars unauthorized users from accessing or updating data in certain fields such as the Salary field.