RFID: blocking wallets, tech, and toll transponders

That’s always been my understanding.

Reading NFC/RFID at a distance is definitely possible. That’s how, for example wireless toll-payment systems (e.g. E-ZPass) work. But in order to work reliably at those distances, they require a powered transmitter in your car and a fairly large receiver antenna (the big square antenna you see above each toll booth lane).

Fujitsu (among others) sells RFID-based self-checkout equipment, where a retailer tags every item in the store. You just walk through the lane and it detects every item you picked up and will bill you to a card you have on-file (or asks you for payment if you don’t have a card on-file).

But both of these are very different from being able to scan the cards in your wallet from across the street. Given the power required to activate the card, you’d need to walk through a gauntlet (like the Fujitsu system), or the attacker would need some pretty large amounts of equipment.

And even then, the attack won’t be meaningful. Contactless payment cards don’t transmit your account information (e.g. the data printed on the card). Instead the on-board EMV chip actively participates in a secure transaction with the bank, where the data transmitted is all encrypted. Although a third party might be able to activate the card with a strong enough signal, he would not be able to get the information necessary to clone the card.

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