Patent ID: 8866594

Claim:
A method for a Radio Frequency Identification (RFID) reader containing a reader key to authenticate a plurality of RFID tags, each containing a tag key, the method comprising: receiving a reader challenge from a verification authority; determining a reader response based at least on the reader challenge and the reader key; sending a first message including at least the reader response but not the reader key to the verification authority; authenticating each tag in the plurality of tags by: receiving a respective tag identifier from each tag; challenging each tag with a respective tag challenge; receiving a respective tag response based at least on the respective tag challenge and the respective tag key but not including the respective tag key; sending a second message including at least the respective tag identifier and the respective tag response to the verification authority; and receiving a reply from the verification authority; and storing a plurality of tag responses from the plurality of tags before sending at least one of the plurality of tag responses to the verification authority.