Your theft light keeps blinking while driving?

Why my anti theft light blinking while driving? When it's flashing rapidly with the ignition switch in the lock or off position there's no communication between them or in most cases the key's not recognized or needs programmed to the vehicle again with a scan tool which you'll probably need towed somewhere to program the key to get this corrected, now if it stays solid while driving that indicates immobilizer activation due to an improper or bad key used to turn vehicle on