Not true, at least with KDE 4.6.0.
It depends on whether you are using knetworkmanager (which does require Kwallet), of the plasmoid network manager applet (whether to use Kwallet is then configurable).
With the plasmoid, if you click on the network manager icon in the tray, then click on “manage connections”, a settings screen comes up. Click on “Other” in the left column of that screen, and then you will find a selection available between
Store connection secrets: Do not store (always prompt); in file (unencrypted); in secure storage (encrypted)
The default is the third of those, which uses Kwallet. But you can select either of the others. I chose to store mine in a file (unencrypted)
The network key is then stored in a file in $HOME/.kde4/share/apps/networkmanagement/connections
(in my case “/home” is an encrypted partition, which I consider secure enough for a WiFi key)
Thanks for your comments nrickert. In case there is someone that does not know how to load the NetworkManager Plasmoid, here is how you get it:
In order to install the NetworkManager Plamoid you need to install the package called plasmoid-networkmanagment which requires that you remove NetworkManager-kde4.
To do this go to:
YaST / Software / Software Managerement and search on plasmoid. When you check the package plasmoid-networkmanagment you will get an option to uninstall NetworkManager-kde4 or to not install plasmoid-networkmanagment so elect to delete the package NetworkManager-kde4. If all goes well you need to restart openSUSE to start using the new one.
If the Network Management Plasmoid does not automatically appear in the bottom right hand corner, then select the Panel Tool Box button, also in the bottom right by default, then select add widgets. Enter the search term network. When you see Network Management, double click on this and the Network Manager icon should appear next to the Panel Tool Box Button.
Be aware that I am using all NetworkManager files from the original openSUSE repositories. If you mix up NetworkManager versions, such as those that can be found in the GNOME or KDE specific repositories, NetworkManager can stop working properly. In general you should ONLY add in Packman to the default repositories that have been added for you when you installed openSUSE.
Be for warned about this problem of mixed version of the NetworkManager.
Thank You,