US 11,951,759 B2
Magnetic PUF with predetermined information layer
Keith Bryan Hardin, Lexington, KY (US)
Assigned to LEXMARK INTERNATIONAL, INC., Lexington, KY (US)
Filed by Lexmark International, Inc., Lexington, KY (US)
Filed on Sep. 2, 2022, as Appl. No. 17/902,779.
Application 17/902,779 is a continuation of application No. 16/817,027, filed on Mar. 12, 2020, abandoned.
Claims priority of provisional application 62/822,510, filed on Mar. 22, 2019.
Prior Publication US 2022/0410612 A1, Dec. 29, 2022
Int. Cl. B42D 25/45 (2014.01); B42D 25/369 (2014.01); B42D 25/373 (2014.01); G06K 19/06 (2006.01); G06K 19/08 (2006.01)
CPC B42D 25/369 (2014.10) [B42D 25/373 (2014.10); B42D 25/45 (2014.10)] 5 Claims
OG exemplary drawing
 
1. A method of simultaneously reading a location of a known element and a random element such the locations of the known element and the location of the random element are paired, thus tying the locations together, comprising:
providing a physical information layer (“PIL”) with a conducting material;
placing the PIL over a physical unclonable function element (“PUF”), where the PIL has a conducting material that is at least one order of magnitude larger than a pre-magnetized particle within the PUF, further wherein the PIL is constructed from a material that does not substantially alter a static magnetic field created by the pre-magnetized particles and a matrix dielectric material;
using a sensor to simultaneously detect the conducting material of the PIL and the pre-magnetized particles in the PUF, wherein the sensor distinguishes between the conducting material and the pre-magnetized particles, further wherein the PIL uses the conducting material locations as a point of reference when paired with the pre-magnetized particles in the PUF that orient an enrollment of a magnetic profile of the PUF; and
using the PIL to find a match in an enrolled database for the magnetic profile for verification against a unique random magnetic information.