An apparatus having a carrier with circuit structures including a complex impedance has a measurement unit implemented to measure the complex impedance of the circuit structures at a first time to get a first result and at a later second time to get a second result. Further, either a control implemented to enable operation of a component or to judge whether unauthorized to the component has taken place in dependence on whether the first result matches the second result, or an interface implemented to transmit the first result and the second result in a wireless or wired manner to such a control are provided.In that way, specifically embedded systems without integrated security functions can be upgraded with cryptographic routines in a simple and cost effective manner.