Hi Michelle, there are many secure file transfer protocols available, the best choice will usually depend on the source and target systems. Most folks use SFTP, SSH, or SCP. Third party transfer tools are also popular if the workload justifies the expenditure. A couple of these we see regularly include WinSCP for windows and NDM for multi-platform including mainframe. The masking engine will connect to the directory containing files to be masked using either FTP or SFTP so you may want to revisit ability to use SFTP.