Secure File Transfer

File transfer between Linux systems (and perhaps all POSIX systems in general) is in some ways a neglected subject. The arcane protocols in common use are far from secure, and the SSH replacements offer too much power and complexity. Servers holding highly sensitive data (such as credit card numbers, SSNs, birthdates and so on) often must accept file transfers, but greatly restrict remote visibility and administration, which is hard with the well known tools.