Compromise of Credit Card Numbers

Recently FireEye published an intelligence report stating that a previously unknown cybercrime group has hacked into numerous organizations in the retail and hospitality sectors to steal an estimated 20 million payment cards, collectively worth an estimated $400 million on the "cybercrime" black market.

To a near approximation, all credit card numbers more than a few months old are public. The market price has dropped to pennies. We are all equally targets of opportunity. That any one of us has not been a victim of fraud is mere chance. They have so many that they simply cannot get to us all.

The brands are at fault for marketing a broken system, one that relies upon the secrecy of credit card numbers but which passes them around and stores them in the clear. Their business model is at risk. They have technology, EMV, tokenization, and checkout proxies, but the first is too slow for many applications and they are not promoting the other two to merchants or consumers.

Issuers take much of the fraud risk. They are attempting, with some short run success, to push this to the merchants.  However, with merchants and consumers, they share in the risk of our broken system.

As the referenced report suggests, bricks and mortar merchants, particularly "big box" retailers and hospitality,  are finding that both issuers and consumers are blaming them for the disclosure of the numbers. Issuers are charging back fraudulent transactions. and suing merchants for the expense of issuing new cards after a breach. Their systems are being penetrated and numbers ex-filtrated wholesale. Point of sale devices are being compromised, or even replaced, to capture debit card numbers and PINs. These are used to produce counterfeit cards.  Some of these are used to,purchase gift cards or get cash at ATMs. Merchant brands have been badly damaged by bad publicity surrounding breaches. While most of these merchants can resist compromise, there are more than enough to guarantee that some will fall. Merchants can reduce fraudulent transactions by preferring mobile, EMV cards, and by checking cards, signatures, and IDs but all but the first slow the transaction and inconvenience the customer.

Online merchants are the target of all kinds of "card not present" scams and take the full cost of the fraud. While it will not stop the fraud, the online merchants can both protect themselves and speed up the transaction by not accepting credit cards and using only proxies like PayPal, Visa Checkout, Apple Pay, and Amazon.

While, at least by default, consumers are protected from financial loss from credit card fraud, the system relies heavily upon them to be embarrassed by it.  At least on court has agreed to hear evidence as to whether or not consumers as a class are otherwise damaged when their card numbers are leaked to the black market.

All this is by way of saying that as long as anyone accepts credit card numbers in the clear, we will be vulnerable to their fraudulent use. There are now alternatives and we need to promote them, not simply tolerate them. Think numberless, card-less, and contact-less.

Chip and PIN Compared to Chip and Signature

As we begin on the long process of changing credit cards from the obsolete magnetic stripe technology to smart (EMV) "chip" cards, there has been a lot of criticism of the decision of the credit card issuers not to implement "Chip and PIN."  Much of this discussion has asserted that "Chip and PIN" is more secure than the chosen chip card and signature strategy.  Apparently this position is so obvious that it has stifled analysis.

I assert that Chip and PIN is only marginally more secure than Chip and Signature. It protects against the fraudulent use of lost or stolen cards. However, fraudulent use of lost or stolen cards is only a small portion of the fraud. The largest part uses counterfeit cards; chips resist counterfeiting.

For both the individual and the issuer, the best protection against fraudulent use of lost or stolen cards is to report the card lost or stolen. The individual is now protected against any use of the card. The issuer will revoke the card and is now protected against any online use of the card.

Note that the effectiveness of revocation depends in part upon the market. In the U.S., where most transactions take place online, it is very effective. In markets where the infrastructure is less robust and many transactions take place offline, revocation is less effective. Thus in the U.S. issuers are opting for Chip and Signature while in other markets Chip and PIN is chosen.

Note that only the issuers know what the losses are for fraudulent use of lost or stolen cards is, that is, how much fraud might be reduced by the use of a PIN on all transactions. It is fair to assume that they know what they are doing.

Some have asserted that, in the absence of the PIN, security will rely upon clerks to reconcile a signature on the transaction document to,the reference signature on the card.  For most routine transactions we do not rely upon the clerk to verify the signature or even to touch the card. While in some places we still sign a chit, at checkout stands we sign on a little tablet (I hate them.) No one ever checks the signature unless the transaction is disputed. Said another way, at least in the U.S., we rely mostly on possession of a current card to authenticate most transactions; both signatures and PINs are backup and there is little to choose between them?