How can I know security type using CAPABILITIES? about iphone-wireless HOT 2 OPEN

I have found out the solution. Have a look the below. You can do more details 
using the wep, wpa, rsn. Thanks.

int adhoc = [network objectForKey:@"AP_MODE"];

if (adhoc == 1) {

ret =@"AdHoc network";

} else {

id wep = [network objectForKey:@"WEP"];

id wpa = [network objectForKey:@"WPA_IE"];

id rsn = [network objectForKey:@"RSN_IE"];

if(wep) {
    ret =@"Secured network (WEP)";
} else if (wpa && rsn) {
    ret =@"Secured network (WPA, WPA2)";
} else if (wpa) {
    ret =@"Secured network (WPA)";
} else if (rsn) {
    ret =@"Secured network (WPA2)";
} else {
    ret =@"Open Network";
}

}

kikyound's code is work,thx!