the invention provides a system , a secure device and a method for authenticating dynamically a host device with a secure device without modifying hardware or basic functional software of the host device . an authentication engine implemented in the secure device allows detecting non - authorized host devices or illegal secure devices environment . the secure device is locally connected to the host device comprising at least one processor configured for handling a plurality of hardware or software parameters defining the functioning behavior of the host device . a memory associated to the processor stores a plurality of reference hardware and software parameters . the secure device monitors the behavior of the host device both in terms of hardware and software . after comparison with the reference parameters , the host device is considered as authentic or authorized only when the values of counters associated to the hardware and software parameters are within an acceptable .