The driver uses the LDAP protocol to communicate with the LDAP server. Most LDAP servers allow non-encrypted (clear-text) connections. Additionally, when configured correctly, some LDAP servers allow SSL-encrypted connections. SSL connections encrypt all traffic on the TCP/IP socket by using a public/private key pair. The actual LDAP protocol doesn’t change, but the communication channel performs the encryption.
The procedure for enabling SSL connections differs slightly from one LDAP server to another. This document covers the process for enabling SSL connections when using Netscape Directory Server 4.12. If you are using another LDAP server, the procedure is similar.