Impinj, Inc.
Item identification via RFID tag secret

Abstract:

A method is provided to determine unique identifiers. A physical item has an RFID integrated circuit (IC) having a unique identifier and a secret. The RFID IC may be configured to provide an identifier portion and a response to a previously sent challenge, where the identifier portion by itself is insufficient to completely identify the IC or item and the response is based on the challenge and the secret. Attempts are made to verify the response using a set of potential secrets determined using the identifier portion. If the response is successfully verified using a certain secret, the secret may then be used to determine one or more other identifier portions. The unique, complete identifier may then be determined from a combination of at least the identifier portions.