In 2004, when the U.S. State Department first started talking about embedding RFID chips in passports, the outcry from privacy advocates was huge. When the State Department issued its draft regulation in February, it got 2,335 comments, 98.5 percent negative.

In response, the final State Department regulations, issued last week, contain two features that attempt to address security and privacy concerns. But one serious problem remains.

Before I describe the problem, some context on the surrounding controversy may be helpful. RFID chips are passive, and broadcast information to any reader that queries the chip. So critics, myself included, were worried that the new passports would reveal your identity without your consent or even your knowledge. Thieves could collect the personal data of people as they walk down a street, criminals could scan passports looking for Westerners to kidnap or rob and terrorists could rig bombs to explode only when four Americans are nearby. The police could use the chips to conduct surveillance on an individual; stores could use the technology to identify customers without their knowledge.

RFID privacy problems are larger than passports and identity cards. The RFID industry envisions these chips embedded everywhere: in the items we buy, for example. But even a chip that only contains a unique serial number could be used for surveillance. And it’s easy to link the serial number with an identity — when you buy the item using a credit card, for example — and from then on it can identify you. Data brokers like ChoicePoint will certainly maintain databases of RFID numbers and associated people; they’d do a disservice to their stockholders if they didn’t.

By Bruce Schneier

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