US 11,775,958 B2
Device security with physically unclonable functions
Kamran Sharifi, Toronto (CA); Jeremy Wade, San Francisco, CA (US); Bertram Leesti, Toronto (CA); Afshin Rezayee, Richmond Hill (CA); Yue Yang, Thornhill (CA); and Max Joseph Guise, San Francisco, CA (US)
Assigned to Block, Inc., Oakland, CA (US)
Filed by Block, Inc., San Francisco, CA (US)
Filed on Jul. 6, 2022, as Appl. No. 17/858,901.
Application 17/858,901 is a continuation of application No. 16/825,921, filed on Mar. 20, 2020, granted, now 11,386,419, issued on Jul. 12, 2022.
Application 16/825,921 is a continuation of application No. 16/593,770, filed on Oct. 4, 2019, granted, now 11,423,391.
Application 16/593,770 is a continuation of application No. 15/942,299, filed on Mar. 30, 2018, granted, now 10,438,190, issued on Oct. 8, 2019.
Application 15/942,299 is a continuation in part of application No. 15/844,510, filed on Dec. 15, 2017, granted, now 10,819,528, issued on Oct. 27, 2020.
Claims priority of provisional application 62/617,993, filed on Jan. 16, 2018.
Claims priority of provisional application 62/534,181, filed on Jul. 18, 2017.
Prior Publication US 2022/0414646 A1, Dec. 29, 2022
Int. Cl. H04L 9/32 (2006.01); H04L 9/08 (2006.01); G06Q 20/34 (2012.01); G06Q 20/32 (2012.01); G07F 7/08 (2006.01); G07F 7/10 (2006.01)
CPC G06Q 20/341 (2013.01) [G06Q 20/3226 (2013.01); G06Q 20/3278 (2013.01); G07F 7/0873 (2013.01); G07F 7/1016 (2013.01); H04L 9/0866 (2013.01); H04L 9/3278 (2013.01); H04L 2209/56 (2013.01); H04L 2209/805 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method, comprising:
receiving, with circuitry, first physically unclonable function (PUF) data from a first PUF source of a payment reader, the first PUF data generated by the first PUF source in response to a first challenge;
receiving, with the circuitry, second PUF data from the first PUF source or a second PUF source, the second PUF data generated by the first PUF source or the second PUF source in response to a second challenge;
comparing, with the circuitry, the first PUF data and the second PUF data;
determining, with the circuitry based on the comparing, a degree of randomness of the first PUF source in generating the first PUF data, wherein the determining comprises determining a value indicating the degree of randomness; and
comparing, with the circuitry, a threshold to the value indicating the degree of randomness; and
controlling whether the payment reader uses PUF values from the first PUF source to perform a secure operation for a payment transaction based on the comparing the threshold to the value indicating the degree of randomness that was determined.