Re: Attack of the clones
You dont understand because you dont understand how EMV works maybe?
Anyway, short answer
The terminal generates a random number that is sent to the card along with a bunch of transaction info. The card then uses a secret key to generate an ARQC. The terminal then sends the random number + transaction information to the issuer who also hold a copy of the secret key. The issuer then uses the information supplied to the chip to recreate the ARQC and compare it to the one the chip generated. You can check the EMV CO manuals if you want to investigate further.
If you understand how it works you will understand why cloning a contactless transaction so you can use it later in a contactless terminal wont work because you can't predict the random number that the terminal will send to the card when you attempt to replay it.