SSL is based on the concepts of public-key cryptography. Although TLS (Transport Layer Security) is functionally a superset of SSL, the names are used interchangeably.
At a high-level, a server which supports SSL needs to have a certificate, a public key, a private key, certificate, key, and security databases. This helps assure message authentication, privacy, and integrity.
To authenticate with SSL, the calendar client establishes an SSL session with the server and submits the user’s certificate to the server. The server then evaluates if the submitted certificate is genuine. If the certificate is validated, the user is considered authenticated.
If you use SSL for authentication, you need to obtain a server certificate for your Calendar Server. The certificate identifies your server to clients and to other servers. Your server can have more than one server certificate with which it identifies itself. Your server can also have any number of certificates of trusted Certification Authorities (CAs) that it uses for client authentication.
For more information on SSL, see the Sun Java System Calendar Server 6.3 Administration Guide.