Activation Token

iTunes gets three things from the phone, the DeviceID, the IMEI, and the ICCID. This is called the token and is unique to every iPhone. This token is then sent to the apple server (alfred.apple.com) via SSL. Apple uses their private key to sign the token and transmits it back to iTunes. iTunes then calls AMDeviceActivate with this signed token. The device gets the token and checks whether or not the signature matches the token. If it does, the device is activated. A patched lockdownd circumvents these checks rather then to provide a valid token. (To create a valid token someone needed Apple's private key.)

{
 "UniqueDeviceID" = "aabbccdd......";
 "InternationalMobileEquipmentIdentity" = "1234....";
 "IntegratedCircuitCardIdentity" = "1234...";
}

Now the NCK and several other fields have also been added.