What is FTPS (FTP over SSL)?

FTPS (commonly referred to as FTP/SSL) is a name used to encompass a number of ways in which FTP software can perform secure file transfers. Each way involves the use of a SSL/TLS layer below the standard FTP protocol to encrypt the control and/or data channels.


In explicit mode (also known as FTPES), an FTPS client must "explicitly request" security from an FTPS server and then step-up to a mutually agreed encryption method. If a client does not request security, the FTPS server can either allow the client to continue insecure or refuse the connection.


Negotiation is not allowed with implicit FTPS configurations. A client is immediately expected to challenge the FTPS server with a TLS/SSL Client Hello message. If such a message is not received by the FTPS server, the server will drop the connection.

To establish an FTPS (implicit TLS/SSL) or FTPES (explicit TLS/SSL) connection with an FTP site using WISE-FTP, select the connection type FTPS or FTPES in the Site Manager dialog box and define the settings via the Advanced button to select an Authentication method.