Cloaking RFID tags

We propose two approaches to cloak RFID tags using a light-weight symmetric key algorithm called Hummingbird (HB), a state-full, rotor-based system. Deployment of Radio Frequency Identification (RFID) at the individual item level has stalled, partially due to concerns over privacy. To realize the full potential of both increased efficiency in the supply chain and promising new capabilities, RFID tags need to be pushed down beyond the cases and pallets that they are used to track now. In order to gain general acceptance, consumers must feel they have control over the tags they possess. HB has been shown to provide high security within reach of the limited resources of a tag. The proposed approaches provide for tag security by silencing a tag unless it is queried by an authenticated reader, while providing a security model that consumers will understand and with which they will feel comfortable. We conclude with a discussion of the challenges of cloaking tags and show how our protocols may be effectively applied in different environments.