It'd be unlikely to have much use outside the one specific situation I find myself in, but it'd be interesting to have a variant on a one-click hoster that works by setting up a temporary one-off SFTP account. Like, you sign up to provide a file named X, and you can securely upload a thing and it gets stored in a server, which won't let you download X back. Someone else creates an account to download the same-named file, and it gives them a similar temporary SFTP account
so the username/password you're given is one use only, the whole thing is fully encrypted the entire upload and download, and for someone else to MITM it, they'd either need to control the server, or spy on your conversation and sign up to receive it before the intended recipient could
and since only one person can sign up to get the file, this MITM would be obvious: the intended recipient would go "hey wait I can't sign up because someone else got it"
@immibis Trying to transfer some large-and-sensitive data from an semi-anonymous donor to a place it can be archived, and having it accidentally leaked or intercepted before it can be properly sanitized would be very bad