PIN OK Attack

The group of attacks on EMV/chip card present transactions. The idea is to bypass PIN checks using the "Offline PIN" cardholder verification methods. In order to do so, hackers need to implement the man-in-the-middle attack which will tamper the response from the card from "63c2" (PIN verification failed, 2 tries left) to "9000" (PIN was correct). After that the terminal will request an online cryptogram and the card will provide it.