However, the problem you have with FTPS and SFTP is although the files are securely transferred to your server,...
once they're uploaded, anyone who accesses the server can see them, because they aren't encrypted. With this in mind, I prefer your first solution, which is to have your hosts encrypt the files using the recipients public PGP key. This option not only ensures the files are encrypted while in transit, and when at rest, but also only the intended recipient can decrypt and view the files. The best solution to your problem, however, is probably a combination of both PGP-encrypted files and a secure FTP connection. Because even if your PGP encrypted files are secure, if your hosts use plain FTP to upload files to your server the username and password used to access the server are sent in the clear. An attacker could potentially steal this information and use it to gain access to the FTP server and upload malicious files or delete existing files.
Dig Deeper on Network Protocols and Security
Related Q&A from Michael Cobb
An old Java vulnerability was discovered to have been ineffectually patched. Expert Michael Cobb explains how this happened and what can be done to ...continue reading
Google's Certificate Transparency tool publicly logs certificates issued by CAs. Expert Michael Cobb explains how the log viewer works to improve ...continue reading
Crowning the most secure web browser is difficult, with research often turning up biased results. Expert Michael Cobb explains how to make a choice ...continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.