Tiny Flaws Can Be Tracked to Make Mass-Produced RFID Tags Unique and Unclonable

Source: http://www.popsci.com/technology/article/2010-03/tiny-flaws-make-rfid-tags-physically-unclonable

Can't touch this

Tiny manufacturing flaws on the atomic level might cause most companies to throw up their hands, but MIT-spinoff Verayo saw them as the key to creating the perfect anti-counterfeiting tags for everything from Walmart DVD shipments to futuristic passports. The company's radio frequency identification (RFID) tags rely upon no two chip being exactly alike on the atomic level, Technology Review reports.

Miniscule flaws because of a slightly thicker or thinner wire can mean tiny variations in how fast a circuit works on a chip. Srini Devadas, an electrical engineer at MIT and Verayo founder, saw that as as the key to creating physically unclonable devices.

Devadas realized that running a series of signals through the imperfect circuits can create a string of numbers unique to each circuit. The string of numbers became the basis for a whole series of mathematical equations that create many challenge and response pairs unique to the security of each chip.

That means a forger can't hope to copy an RFID chip even if he or she intercepts the RFID signals being transmitted, because it's literally impossible to perfectly replicate each and every flaw.

Someone could still beat the system by getting their hands on the challenge-response pairs for RFID tags. But these imperfect circuits should form just one part of a much larger defense against counterfeiting, experts say.

Verayo already has contracts for even more sophisticated systems with the U.S. Department of Defense, and other companies have begun developing physically unclonable security systems.

If you're not as worried about counterfeiters, and just want to keep track of all your personal gear, there are already DIY RFID kits that have you covered.

[via Technology Review]