You can access the 'Web Server Security' through the 'Web Server Settings' dialog, or right-clicking on the 'Web Server Status Panel' , or using the 'Web Server Action Menu'.

Authentication will secure your published files and should be used specially if you have a public IP address. Authentication is handled by the operating system and usernames, passwords and permissions are defined by you. Microsoft Windows uses 128-bit encryption to handle secure logons. All access to pages and resources are displayed in real-time and logged.

You can also not use authentication at all but that is not recommended unless you are on a safe local network.

Also you can limit what users can access what simply by changing the 'User profile' granted resources.