Method of detecting an unauthorized exchange of components in the case of a technical system, where the control unit (1) sends an encoded message (3) to a component (2) to be checked, in a data field of the message (3) a randomly generated or not easily reproducible value (5, 6) being entered, which...http://www.google.com.hk/patents/US7747869?utm_source=gb-gplus-share專利 US7747869 - Process for detecting defective component exchanges
