Device for protecting against unauthorised use of software - contains external data generator providing input to computer dependent on output from it, which detects manipulation attempts

The device protects against the unauthorised use of software and contains at least one external data generator connected to the signal input of a computer system, which generates data dependent on data received from the computer system. The computer system is placed in a fault state or the software deactivated when no or faulty data are received via the signal input. If the data generator detects an attempt to manipulate its hardware and/or the received data it changes the contents of a memory, resulting in faulty or no data output and/or changes to user authorisation. ADVANTAGE - The device is designed to make it extremely difficult to analyse the function of the data generator from its inputs and outputs or its outputs alone.