You can add security to your DB2 subsystem by using the Resource Access Control Facility (RACF). RACF is a component of the SecureWay Security Server for z/OS. Other, equivalent security packages are available on the market.
Use of RACF will prevent unauthorized users from having access to the system. RACF can be used to protect a variety of resources in DB2 and to check the identity of DB2 users. An exit routine that runs as an extension to DB2 is part of the Security Server and can also provide central control authorization to DB2 objects.
For more information on security options, refer to Chapter 3.