US 12,143,479 B2
Ultra high entropy material-based non-reversible spectral signature generation via quantum dots
Stacey L. Franklin, Hawthorne, CA (US); and Kalin Spariosu, Thousand Oaks, CA (US)
Assigned to Raytheon Company, Tewksbury, MA (US)
Filed by Raytheon Company, Waltham, MA (US)
Filed on Aug. 2, 2023, as Appl. No. 18/363,853.
Application 18/363,853 is a division of application No. 17/653,761, filed on Mar. 7, 2022, granted, now 11,784,805.
Prior Publication US 2023/0396424 A1, Dec. 7, 2023
Int. Cl. H04L 9/08 (2006.01); G02F 2/02 (2006.01); H04L 9/32 (2006.01)
CPC H04L 9/0852 (2013.01) [G02F 2/02 (2013.01); H04L 9/3236 (2013.01); H04L 9/3278 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of making a physically unclonable function (PUF) device, the method comprising:
(a) forming a layered structure by:
(a-1) providing a first layer of a first optically clear medium;
(a-2) infusing a first random distribution of first quantum dots (QDs) of a first type, disposed at a first plurality of random locations, into the first layer wherein the first type of QDs are configured to generate a first color in response to being excited by an excitation source;
(a-3) partially curing the first layer such that at least a first portion of the first random distribution of first QDs are fixed into at least a first portion of the first plurality of random locations and such that at least a second portion of the first random distribution of first QDs are not in a fixed position;
(a-4) applying a second layer of a second optically clear medium, over the first layer of optically clear medium, after partially curing the first layer of optically clear medium;
(a-5) infusing a second random distribution of second quantum dots (QDs) of a second type, disposed at a second plurality of random locations, into the second layer of optically clear medium, wherein the second type of QDs are configured to generate a second color in response to being excited by the excitation source, wherein the second color is different than the first color, wherein the infusion of the second random distribution of second QDs is configured so that at least a third portion of the second random distribution of second QDs are intermingled with the second portion of the first random distribution of first QDs; and
(a-6) curing the second layer of optically clear medium to a degree sufficient to ensure that both the first random distribution of first QDs and the second random distribution of second QDs are substantially fixed into position; and
(b) operably coupling a detector and an excitation source to the layered structure so that the excitation source is configured to direct light to the first layer of optically clear medium and to the second layer of optically clear medium and so that the detector is configured to detect a pattern of light that arises from directing light at the first random distribution of first QDs and at the second random distribution of second QDs; and
(c) constructing and arranging the excitation source, first layer of optically clear medium, second layer of optically clear medium, and detector so that the light and the pattern of light are externally unrevealed.