The problem with this is it's only as secure as the password, and most people choose weak passwords.

Edit: Another is you need to manually enable the checkmark to 'encrypt file names'. Otherwise all file names are in the clear.

TLDR at the bottom.

It seems the answer is Brian Warner's magic-wormhole. You're gonna see lots of file transfer sites with wormhole in their name, but if you want security you should use the original one, which is BW's m-w.

It is implemented in Python [1], so it's hard to install.

So someone made a Go version of it [2] that has binaries for windows, Mac, Linux, BSD etc. But it's command line so maybe not suitable for lay people.

So another person made a GUI for it that also has binaries for all OS [3].

Also there is an android app [4]. Someone needs to implement an iOS one.

[1] https://github.com/magic-wormhole/magic-wormhole/

[2] https://github.com/psanford/wormhole-william/

[3] https://github.com/Jacalz/wormhole-gui/

[4] https://github.com/psanford/wormhole-william-mobile/

TLDR: ask them to install [5] and [6].

[5] https://github.com/Jacalz/wormhole-gui/releases/

(click on 'Assets' under 'Latest release' and download the zip or tar.gz for your OS)

[6] https://play.google.com/store/apps/details?id=io.sanford.wor...

Try it, it's usage is cute and really feels like magic.

. .

Edit: Discussion from few days ago. The creator is in the comments.

https://news.ycombinator.com/item?id=27262193