As you may know, starting in October the credit card companies are changing the rules on credit card liability for transactions where the credit card is present at the location of the purchase.  The idea is to encourage merchants and financial institutions to adopt the “EMV” (Europay/MasterCard/Visa) “chip” credit cards.

The EMV cards are generally considered to be more secure, because the chip creates a unique transaction code for each transaction, whereas if someone manages to read the magnetic stripe on a traditional credit card (and acquires the 3 digit verification number), there is nothing to stop repeated use of that credit card.

However, readers should be aware that there is a downside to the EMV chip technology.  While magnetic strips can be easily read (say, after theft of a card, or by a physically compromised ATM), magnetic strips cannot be read remotely.   On the other hand, the card chips can be accessed remotely.  Thus information on these new EMV cards can be read from a few inches away, even while the card is in your wallet or purse, by anyone passing near to you.  While some cards do not reveal account numbers this way (American Express claims to be in this group), others have been shown to do so.

So, what can be done to protect your new EMV credit and debit cards?  The answer is to protect them by blocking radio frequencies (RF) from reaching the card when it is not in use.  One suggestion is to wrap them in aluminum foil.  While this is 100% effective (providing what is known as a Faraday cage around the card), it is bulky and inconvenient.  A less bulky and more convenient alternative is to place the cards in an RFID shield sleeve.  These sleeves, available from retailers (Amazon, REI and many others), are inexpensive, and do not take up appreciable space in your purse or wallet, and should also serve as a reasonably effective Faraday cage to protect your cards – not only credit cards, but any card that uses this kind of chip technology, which might include educational institution cards, company security access cards, driver licenses and others.