In addition to encrypted passwords and encrypted connections, you can secure your system by using the file permissions of the operating system, by limiting access to the security configuration files, and by limiting access to the servers.
Limiting access to the configuration files Configure security in such a way that each security file is readable only by those programs or users that require it. The security configuration files installed with software, which should be edited after installation, are readable by anyone.
Limiting access to servers The option to the command provides another method of access control. This option limits the hosts that can connect with the server. Before other security measures occur, incoming connections must pass the option before authenticating.
Using file permissions You can limit access to the security configuration files by using the permissions feature of the operating system. Allow only selected users to access the files. The users must include those who launch the applications requiring access to the authentication records.