In 2010, Steven MURDOCH, Ross ANDERSON, and their team disclosed a weakness in the EMV protocol. Most Credit / Debit card equipped with a chip use the EMV (Europay, MasterCard, Visa) protocol. The vulnerability enabled to bypass the authentication phase for a given category of transactions. The card does not condition transaction authorization on successful cardholder verification. At the time of disclosure, Ross’s team created a Proof Of Concept using an FPGA. The device was bulky. Thus, some people minored the criticality.
The team of David NACCACHE recently published an interesting paper disclosing an exemplary work on a real attack exploiting this vulnerability: “when organized crime applies academic results.” The team performed a non-destructive forensic analysis of forged smart cards that exploited this weakness. The attacker combined in a plastic smart card the chip of a stolen EMV card (in green on the picture) and an other smart card chip FUN. The FUN chip acted like a man in the middle attack. It intercepted the communication between the Point of Sales (PoS) and the actual EMV chip. The FUN chip filtered out the VerifyPIN commands. The EMV card did not verify the PIN and thus was not blocked in case of the presentation of wrong PINs. On the other side, the FUN chip acknowledged the PIN for the PoS which continues the fraudulent transaction.
Meanwhile, the PoS have been updated to prevent this attack.
This paper is an excellent example of forensics analysis as well as responsible disclosure. The paper was published after the problem was solved in the field. It discloses an example of a new potential class of attacks: Chip in The Middle.
Law 1: Attackers will always find their way. Moreover, they even read academic publications and use them.