On a wireless network, the WPA key is a passphrase that protects the network from outside intruders. If a wireless router is set up with WPA encryption, you need the WPA key for network access and to make changes network settings.Gaming devices that allow you to play games online also generally require you to know the WPA key if you plan to connect them to the Internet wirelessly. If your WPA key shows up as all asterisks (*******), reset the key on your router so that you know what it is. 2  If you do this, you generally also need to change the key on every wireless device you own.