There was always this context menu, now it is gone.
There is in konqueror, but not in Dolphin.
It’s easy to create it. Just copy /usr/share/kde4/services/ServiceMenus/encryptfile.desktop here:
/usr/share/kservices5/ServiceMenus/encryptfile.desktop
This service menu is provided by kgpg, which hasn’t been ported to KF5 yet, so it only installs it for KDE4.
If you think this should be fixed in the openSUSE packages(we could add a symlink /usr/share/kservices5/ServiceMenus/encryptfile.desktop like we did in other packages so that it shows up in Dolphin as well), please file a bug report at http://bugzilla.opensuse.org/ (same username/password as here) so that this won’t get lost.