safe remote upload-only access
What is a good, secure way to give a remote user on a Windows machine
access to a Debian machine so that he may upload proprietary files
every few days?
The Debian machine is behind a router/firewall and has a dynamic ip
address, but it does have a domain name registered with dyndns.com.
The Debian machine is not running 24/7; but this is not a problem,
because the transfer can be coordinated by a telephone call.
The Windows user should not be allowed to browse the file system of
the Debian machine. Giving him an account would allow him to browse
the entire home directory.
I have considered rsync, scp, and setting up a ftp server. My primary
concern is safety of the Debian host.