It's possible I suppose, it depends whether the dongle is designed for that.
Note: You only need to use WEP security if you have a DS or DS Lite. The DSi, DSi XL, 3DS and 3DS XL support WPA and WPA2 just fine.
DSi/DSi XL: on connections 4, 5 and 6 only. 3DS/3DS XL: normally, not under DS Connections (these get seen as DSi connections 4, 5 and 6 by compatible titles).
Note#2: Only DSi Enhanced (or 3DS) titles such as Pokemon Black, White, Black 2 and White 2 will support WPA and WPA2. --- We shall rise again to start anew. White FC: 0862-2660-4156 / 3DS FC: 2492-4470-1418 / White 2 FC: 4556-7836-2644