Patent ID: 8332645
Filing Date: 2012-12-11
Classification: H04L

Abstract:
1. A method for maintaining secure communication between a passive RFID tag including circuitry having stored therein object identifying data, and an interfacing RFID reader containing circuitry to read and write tag data and which is connectable with a back-end processor and database that aggregates and utilizes tag data collected by the RFID reader from the RFID tag comprising the steps of: a. initializing both the RFID reader and the RFID tag with (i) an initial array B=a[1 . . . n], (ii) i=1 and (iii) a keyentry=n−(i−1)mod n; b. creating by the RFID tag a new random vector b, and seed X=a[keyentry]; c. calculating a key message by the RFID tag as s=(X,b) and sending the key message to the RFID reader wherein watermarks are added to the message sent by the RFID tag to the RFID reader; d. receiving the key message by the RFID reader and calculating if X=a[keyentry], and if so, sending a positive message to the RFID tag, and if not so, sending a negative message to RFID tag; and e. initiating an action by the RFID tag responsive to receiving a positive message.