iCal Server is Mac OS X Server's shared calendar and scheduling service, which lets users and groups access centrally stored calendar data — either using a desktop program such as iCal on Mac OS X, Mozilla Sunbird (www.mozilla.org/projects/calendar/sunbird) on almost any platform, or an optional web-based interface.
The security features you can configure for iCal Server are identical to those of Address Book Server: the authentication method(s) supported and whether to use SSL, resulting in encrypted transfer of all calendar data across the network. If you feel it's essential to protect your calendar data from the possibility of being sniffed by someone watching the Internet traffic between your server and (presumably remote) users, SSL provides an easy way to do that — but for most installations, it's not essential.
Before you can activate SSL for iCal Server, you must already have a valid SSL certificate installed for the domain name in question.
To configure iCal Server's security features, follow these steps:
Open Server Admin, which is located in /Applications/Server.
In the sidebar on the left, select your server.
If no services are listed under the server name, click the disclosure triangle next to the server name to reveal them.
If the service names are dimmed, choose Server Connect, type your username and password if they're not already filled ...