Date Added: Oct 2009
RFID tags are being widely employed in a variety of applications, ranging from barcode replacement to electronic passports. Their extensive use, however, in combination with their wireless nature, introduces privacy concerns as a tag could leak information about the owner's behaviour. In this paper, the authors define two privacy notions, untraceability and forward privacy, using a formal model based on the applied pi calculus, and they show the relationship between them. Then they focus on a generic class of simple privacy protocols, giving sufficient and necessary conditions for untraceability and forward privacy for this class.