Its WEP (Wireless Encryption Protocol)
WAP is Wireless Access Protocol and is used in mobile handsets
WPA is stronger than WEP but WEP does the trick. Hiding SSID is cool too as people scanning for Wireless Access Points will not see your network.
MAC address filtering wil only allow certain PCs to access your network. This is specified by you and further adds security)
Another security method you can use its to turn off DHCP. This will mean that anyone trying to connect will not get given an address to access the network. The trick with this one is to use an oddball IP range instead of the usuall 192.168.0.x that most dumptys use (not secure)