FTP, the method you might be using to transfer files to minerva, is not secure. When you use FTP, all of your data (password, files, etc.) is sent in plain text, which is fairly easy for malicious people to intercept. Because it is insecure, we are in the process of discontinuing ftp access to minerva.
Fortunately, there's a more secure alternative: SFTP. SFTP is like FTP, except that it is encrypted (just like SSH). For information about where to get an SFTP program and how to use it, see the FAQ.
If you need help installing an SFTP program or have any other questions, send email to ca.