The problem is that authorized government officials are not the only ones that can read the signals transmitted from the RFID chip. Researchers have been able to build readers that can catch signals from a passport sitting in someone's pocket or briefcase. The fear is that the signals from the chips, if captured by someone with malicious intentions, could be used to forge passports, since the signals contain crucial information like names, birthdates and places of birth.
Unlike a credit card with an RFID chip, which could function if the chip were removed or damaged, an altered passport is considered invalid by most governments. So, since removing the chip isn't an option, RFID wallets have come out on the market.
RFID-blocking wallets and passport holders, on the surface, look just like any other wallet or passport holder. And those available on the market now are just as stylish, in a broad selection of colors and materials. The difference is that, under the surface, the wallet contains a wire or foil mesh that blocks the radio signals emitted from RFID passports.
The material in the wallet that blocks signals creates a Faraday cage, a place unreachable by radio signals. Elevators are an example of a Faraday cage, as anyone who has tried to use a cell phone while traveling up or down an office building can attest.
RFID-blocking wallets are available from a number of vendors that sell travel paraphernalia, and testimonials on their websites indicate they do, in fact, block RFID signals, but independent testing is hard to find.
At least one thing can be said about RFID wallets: They're more stylish than wrapping a passport in aluminum foil, which might be just as effective.
This was first published in August 2008