»In which we open the hotel door with a carton of cream cheese

I was inadvertently locked out of my hotel room a few days ago: I had left the heavy brass key at the reception desk, and planned on returning before the clerk left for the night at 2300. However, sunset at the beach in Kijkduin was late, and I spent too long watching the windsurfers. As I hastily arranged a ride back to the hotel I imagined covert ways to get in to the room: with a thin credit card? with a picklock set? with my pocket-knife? with someone else's key?

I did not, however, contemplate using cream cheese:

[Lukas] Grunwald cowrote a program called RFDump, which let him access and alter price chips using a PDA (with an RFID reader) and a PC card antenna. With the store's permission, he and his colleagues strolled the aisles, downloading information from hundreds of sensors. They then showed how easily they could upload one chip's data onto another. "I could download the price of a cheap wine into RFDump," Grunwald says, "then cut and paste it onto the tag of an expensive bottle." The price-switching stunt drew media attention, but the Future Store still didn't lock its price tags. "What we do in the Future Store is purely a test," says the Future Store spokesperson Albrecht von Truchsess. "We don't expect that retailers will use RFID like this at the product level for at least 10 or 15 years." By then, Truchsess thinks, security will be worked out.

Today, Grunwald continues to pull even more-elaborate pranks with chips from the Future Store. "I was at a hotel that used smartcards, so I copied one and put the data into my computer," Grunwald says. "Then I used RFDump to upload the room key card data to the price chip on a box of cream cheese from the Future Store. And I opened my hotel room with the cream cheese!"

Much more about RFID hacking in WIRED.