When sending zip archives that contains risky/secure content, you should always encrypt and password protect them. Especially when sending them to clients via email, Dropbox or some other public sharing method. To do that on Linux is very simple. You can do it with commands bellow. When executed you’ll be prompted to enter password.
When adding file, just do this:
zip --encrypt myarchive.zip myfile.txt
But when adding directory with subdirectorys and files, than you should always include “-r” flag to tell zip to use recursion. Otherwise you’ll end up with empty directory and see message like this “adding: behaviour.exchange/ (stored 0%)”
To add directory recursively:
zip --encrypt -r myarchive.zip mydir/