Patent ID: 8917159

Claim:
An RFID tag identifying a product, the tag comprising: a memory means for storing data; a command means responsive to commands from an RFID interrogator; the command means comprising a lock command for changing memory locking lock bits; tag states including a secured state for the tag to execute the lock command; a publicly readable product identification number stored in the memory means; an access password stored in a reserved bank of the memory means; a kill password stored in the reserved bank of the memory means; an index number means stored in a bank of the memory means for use as an index into an indexed table of cryptographic keys that are stored in the RFID interrogator; a header means stored in a bank of the memory means for specifying to the RFID interrogator a method of using a cryptographic key that is stored in the indexed table of cryptographic keys at an index location matching the index number means and with the publicly readable product identification number to cryptographically formulate within the RFID interrogator a formulated access password and a formulated kill password; a means for one or more states of the tag states to transition to the secured state when the RFID interrogator sends to the RFID tag the formulated access password and it is non-zero and identical to the stored access password; and a means for one or more states of the tag states to transition to the killed state when the RFID interrogator sends to the RFID tag the formulated kill password and it is non-zero and identical to the stored kill password.