Check this box to enable the FTP server to support clients using the Transport Layer Security protocol (TLS) protocol. The Security Sockets Layer (SSL) protocol is included in TLS.
After checking the box "Enable TLS security", click the "Security Settings..." button to customize security settings for TLS.
Clicking the "Security Settings..." button is required to specify the certificate (key ring) location. For other security settings, you can use the defaults if desired.