Jamming Tags Block RFID Scanners

RSA Security has developed a countermeasure to block scanning of radio-frequency ID tags, responding to privacy concerns about the tiny devices that would allow retailers and manufacturers to track the whereabouts of their goods within a store and beyond.

The blocker tag, which can be placed over a regular RFID tag, prevents a receiver from scanning information transmitted by a tag by sending the receiver more data than it can read -- the equivalent of a denial-of-service attack. RSA doesn't have immediate plans to market the blocker and is waiting to see whether industry widely adopts RFID technology.

Albrecht was also worried that blocker tags would encourage people to become complacent about surveillance, thinking they could protect themselves from it at will. But she said the blocker tag would work only as long as it was legal.

"You could allow surveillance to be created all around you, thinking the blocker tag would protect you, and then a single stroke of the pen could render a blocker tag illegal by an executive mandate," she said.