The present invention is a system and method for soft modem software
protection using a key. The key is stored in a hardware device in the
modem subsystem and transmitted to the central processing unit (CPU) in a
designated time slot of a serial bus of a computer. In one embodiment, the
key is stored as bit data in the registers of the modem codec. In another
embodiment, the key is stored in a hardware device connected to the
general purpose input output pins of the modem codec. In a further
embodiment, the key is stored in a hardware device connected to the on/off
hook and analog input connections of the modem codec. A second key is
associated with the soft modem software. If the second key is incompatible
with the transmitted key, the operation of the soft modem software is
altered. Altematively, the soft modem software is a customized version
downloaded from an external computer to a local computer. The customized
version has a unique identifier associated with the local computer
associated with it.
