JavaCard OS

Is there an unique identifier for smartcards?
- If yes, how should I read it out from card?
-If no, what property can I use to identify the cards?
Thanks

You can try to read out the CPLC from smart card which is unique to card.

When you issue the card you should set the IIN (issuer identification number) and CIN (card image number) in the card manager. You can then get these to uniquely identify a card. Try it.