×

RFID tags with dynamic key replacement

  • US 9,887,843 B1
  • Filed: 12/21/2016
  • Issued: 02/06/2018
  • Est. Priority Date: 07/02/2013
  • Status: Active Grant
First Claim
Patent Images

1. A method to wirelessly authenticate an item, the method comprising:

  • sending a message to a Radio Frequency Identification (RFID) integrated circuit (IC) associated with the item;

    receiving, from the RFID IC, an identifier and a cryptographic response to the message;

    determining, based on the identifier, a plurality of potential keys including a used key and at least one unused key;

    generating a plurality of processed cryptographic responses, each processed cryptographic response based on the received cryptographic response and a respective potential key in the plurality of potential keys;

    extracting a verification value from a first one of the plurality of processed cryptographic responses;

    if the verification value corresponds to a known value then authenticating the item;

    else;

    extracting other verification values from the other ones of the plurality of processed cryptographic responses; and

    if the other verification values do not correspond to the known value then considering the item suspect.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×