A technique for identifying individual instances of electronic devices. This is done by using a basic RFID reader to read the RF emissions from the electronic device to obtain an emitted electromagnetic spectrum and compare it to a library of emitted electromagnetic spectrums of different instances of that type of electronic device and, based on that comparison, finding a best match and identifying the electronic device as being a particular instance of that type of electronic device. This comparison may be made by computing Euclidean distances between vectors that are based on the measured electromagnetic spectrums.