title: Prevent copying nfc chip signal
body: <p>I'm wondering if NFC chips have some kind of unique identifier? I have Mifare Classic 1K and Mifare Ultralight C stickers that I want NFC phones to read using my android application, is there some common practice to protect the signal so someone can't just come in and scan the data using a generic app (NFC Reader), and write the data to another chip in order to fake my sticker signal. Or, is there a unique ID like how phone UUID works built in these chips?</p>