Abstract: A system (100) and method of improving activation security allows a remote device (104) to identify that there is a difference between a first signal transmitted by a central site (102) and a first signal received by the remote device. A derived number is used. The derived number can be displayed to the user for verbal verification by the user, or the derived number can be used internally of the remote device, or the central site, for verification that is transparent to the user. A significant amount of security is added without substantially altering the communication protocol.