WPA is a reasonable form of security, assuming you have also entered a reasonable strength password (If you didn't need to enter a password when your PC connected wirelessly, then you don't have security orperational
). You may want to look at the broadcast name (SSID) you have set. I at least use something ambiguous that' i'd recognise but doesn't give the game away to neighbours. Alternatively you can turn that off altegether, but that can hinder you, as well as others, even finding your network.