%supported_security = (
    "WPA"    => "WPA",
    "WPA2"   => "WPA2",
    "WEP 64" => "WEP 64",
    ...
);

##</code><code>##

$best_type = $supported_security{"WPA2"}
    // $supported_security{"WPA"}
    // $supported_security{"WEP 128"}
    // ...