PCB: Physically Changeable Bit for Preserving Privacy in Low-End RFID Tags

Consumer privacy is a major concern impeding the wide deployment of radio-frequency identification (RFID) tags in consumer market. To tackle this privacy issue, a simple and effective approach is proposed in this paper via adding one bit called ”physically changeable bit” (PCB) in RFID tags. The PCB bit can and only can be altered ”physically”. It controls whether RFID tags respond to queries sent by RFID readers. In this way, tags can be deactivated and reactivated easily by their owners via a simple device or even with no device. On the other hand, adversaries cannot track tags deactivated by their owners since adversaries cannot reactivate those tags “remotely”. PCB design is based on the fundamental assumption that adversaries have no physical contact with RFID tags owned by others. When extended with multiple built-in PCB bits, RFID tags can be configured to respond with appropriate ID information to queries while still preserving consumer privacy at the same time. PCB design combines the remote-identification benefit of RFID technology together with the safety of current barcode system, and most importantly, easy to be understood and accepted by general consumers.