Protocols for Objects with Multiple RFID Tags

Security/privacy issues are of paramount importance for widespread acceptance and use of RFID tags. Over the past few years, researchers have addressed this issue through lightweight cryptographic means. A majority of existing literature in this area consider communication between a single-tagged object and a single reader or owner of this tag. There are instances where either or both of these may not be valid. For example, an object could have multiple disparate embedded tags in each of its component parts or several identical tags could have been affixed to this object for improving its read rate accuracy. Similarly, several readers (or, owners) may simultaneously have the necessary privilege, keys, etc. to be able to read (or, own) a tagged object as happens with vendor management inventory. In the multiple-tagged object scenario, objects gain and lose tags over time as components are added or removed from the object of interest. We consider the multiple-tagged object scenario and present cryptographic protocols for tag updates. We then present ownership transfer protocols for the multiple-tagged object scenario. We also provide a brief security analysis of the presented protocols.