Comment Re:Could somebody explain this? (Score 1) 36
That sounds like one of the master 3DES key for to generate Application Cryptogram on the chip cards has been leaked. Which is very unusal as those are highly guarded by HSM in place. And it's not the same RSA key to guard the certificates
the master key is used to derive into sub level card keys to used on each chip card.
The application cryptogram is generate on the chip card to uniquely identify the card and transaction context, and used by the EMV host to validate whether the card/transaction is geniune or not.