US 12,468,915 B1
Item identification via RFID tag secret
Matthew Robshaw, Seattle, WA (US); Tan Mau Wu, Seattle, WA (US); and Christopher J. Diorio, Shoreline, WA (US)
Assigned to Impinj, Inc., Seattle, WA (US)
Filed by Impinj, Inc., Seattle, WA (US)
Filed on Sep. 5, 2024, as Appl. No. 18/825,156.
Application 18/825,156 is a continuation of application No. 18/316,311, filed on May 12, 2023, granted, now 12,086,668.
Application 18/316,311 is a continuation of application No. 17/472,770, filed on Sep. 13, 2021, granted, now 11,651,180.
Application 17/472,770 is a continuation of application No. 16/773,393, filed on Jan. 27, 2020, granted, now 11,120,320.
Claims priority of provisional application 62/797,874, filed on Jan. 28, 2019.
This patent is subject to a terminal disclaimer.
Int. Cl. G06K 19/07 (2006.01); G06K 17/00 (2006.01); H04L 9/08 (2006.01); H04L 9/32 (2006.01)
CPC G06K 19/0723 (2013.01) [G06K 17/0029 (2013.01); H04L 9/0861 (2013.01); H04L 9/3226 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for an RFID reader system configured to identify and authenticate an RFID tag storing a tag key and associated with but not storing an item identifier, the method comprising:
at a processor block coupled to a reader module of the RFID reader system:
requesting and receiving, via the reader module, a first identifier from the tag;
sending, via the reader module, a challenge to the tag;
receiving, via the reader module, a cryptographic response from the tag;
determining a set of potential keys associated with the first identifier, wherein each potential key is associated with a different potential identifier;
identifying a correct key, wherein the correct key corresponds to the tag key, by:
failing to recover the challenge from the cryptographic response using a first one of the set of potential keys in a cryptographic algorithm, but
correctly recovering the challenge from the cryptographic response using a second one of the set of potential keys in the cryptographic algorithm; and
selecting the second one of the set of potential keys as the correct key;
using the correct key to authenticate the tag; and
identifying the tag using a potential identifier associated with the correct key as at least part of the item identifier.