US 12,149,938 B2
Dynamically encrypted radio frequency fingerprinting
Zhigang Gao, Twinsburg, OH (US); and Huaiyi Wang, North Royalton, OH (US)
Assigned to Cisco Technology, Inc., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Jun. 15, 2020, as Appl. No. 16/902,071.
Prior Publication US 2021/0392497 A1, Dec. 16, 2021
Int. Cl. H04W 12/106 (2021.01); H04L 1/00 (2006.01); H04W 12/122 (2021.01); H04W 12/79 (2021.01)
CPC H04W 12/106 (2021.01) [H04L 1/0061 (2013.01); H04W 12/122 (2021.01); H04W 12/79 (2021.01)] 14 Claims
OG exemplary drawing
 
1. A method comprising:
determining, at a receiver, a carrier frequency offset (CFO) estimate for a client device;
receiving a packet with an RF signature value marked as from the client device;
generating a receiver cyclic redundancy check (CRC) value using a CRC algorithm based on at least a portion of the packet;
decoding the RF signature value to determine an encoded CFO for the client device using a predefined mapping algorithm, wherein the predefined mapping algorithm was assigned, to the client device, by the receiver;
decoding the RF signature value to determine a client CRC value using the predefined mapping algorithm;
comparing the CFO estimate and the encoded CFO to one or more expected CFO value thresholds;
comparing the receiver CRC value and the client CRC value; and
determining that the comparisons indicate that a difference between the CFO estimate and the encoded CFO is within the one or more expected CFO value thresholds and the receiver CRC value matches the client CRC value; and
in response to the determination that the difference is within the one or more expected CFO value thresholds and the CRC values match, processing the packet.