FTP connections of the File/FTP adapter can be secured by using FTPS, which is FTP over SSL/TLS. The File/FTP adapter acts as an TLS client to the FTP server both in sender and receiver channels.
As in the case of HTTP and SSL, you first have to technically enable FTPS on the corresponding AS Java by installing the appropriate libraries and certificates as described under HTTP and SSL . Then, you configure the actual certificates of the AS Java keystore used for the FTPS connection in the respective File/FTP sender and receiver channels in the Integration Directory.