Security

Security Security of data is important concept in DBMS because it is essential to safeguard the data against any unwanted users. It is protection from malicious attempts to steal or modify data.

There are five different level of security Database system level Operating Network level Physical level Human level

1. Database system level Authentication and authorization mechanism to allow specific users access only to required data.

2. Operating Protection from invalid logins File level access protection Protection from improper use of “superuser” authority. Protection from improper use of privileged machine instructions.

3. Network level Each site must ensure that it communicates with trusted sites. Links must be protected from theft or modification of messages. Mechanisms used Identification protocol (password based) Cryptography

4. Physical level Protection of equipment from floods, power failure etc. Protection of disks from theft, erasure, physical damage etc. Protection of network and terminal cables from wire tapes, non invasive electronic eavesdropping, physical damage etc., Solution Replication hardware- mirrored disks, dual busses etc. Multiple access paths between every pair of devices. Physical security by locks, police etc. Software techniques to detect physical security breaches.

5. Human level Protection from stolen passwords, sabotage, etc. Solution Frequent change of passwords. Use of “non-guessable” passwords. Log all invalid access attempts. Data audits Careful hiring practices.