Physical Unclonable Functions Having Magnetic Particles

Abstract

A physical unclonable function (PUF) apparatus having magnetic particles is disclosed. The magnetic field data and the image view of the magnetic particles in the PUF apparatus are difficult to counterfeit. A PUF apparatus may be incorporated into a user-replaceable supply item for an imaging device. Further, a PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

What is claimed is: 
     
         1 . An apparatus comprising:
 a substrate;   a plurality of magnetic particles dispersed in the substrate, the plurality having an average particle diameter greater than 25 microns.   
     
     
         2 . The apparatus of  claim 1 , wherein the magnetic particles are flakes having an average particle thickness that is less than the average particle diameter. 
     
     
         3 . The apparatus of  claim 1 , wherein the magnetic particles in the substrate have an average particle diameter of between 50 and 1000 microns. 
     
     
         4 . The apparatus of  claim 1 , wherein the magnetic particles contain neodymium, iron, and boron. 
     
     
         5 . The apparatus of  claim 1 , wherein the magnetic particles contain samarium and cobalt. 
     
     
         6 . The apparatus of  claim 1 , wherein the substrate is configured to rotate about an axis. 
     
     
         7 . The apparatus of  claim 1 , wherein the substrate is attached to a gear. 
     
     
         8 . A system comprising:
 a body;   a substrate;   a plurality of magnetic particles dispersed in the substrate, the plurality having an average particle diameter greater than 25 microns; and   a non-volatile memory, wherein the substrate and the non-volatile memory are mounted to the body, and the non-volatile memory contains data corresponding to a magnetic field generated by the magnetic particles.   
     
     
         9 . The system of  claim 8 , wherein the substrate is non-opaque. 
     
     
         10 . The system of  claim 9 , wherein the non-volatile memory contains image data corresponding to the magnetic particles. 
     
     
         11 . The system of  claim 8 , wherein the magnetic particles are flakes having an average particle thickness that is less than the average particle diameter. 
     
     
         12 . The system of  claim 8 , wherein the magnetic particles contain neodymium, iron, and boron. 
     
     
         13 . The system of  claim 8 , wherein the magnetic particles contain samarium and cobalt. 
     
     
         14 . The system of  claim 8 , wherein the substrate is configured to rotate about an axis. 
     
     
         15 . The system of  claim 8 , wherein the substrate is attached to a gear. 
     
     
         16 . A system comprising:
 a body;   a non-opaque substrate;   a plurality of magnetic particles dispersed in the substrate, the plurality having an average particle diameter greater than 25 microns; and   a non-volatile memory, wherein the substrate and the non-volatile memory are mounted to the body, the non-volatile memory contains data corresponding to a magnetic field generated by the magnetic particles, and image data corresponding to the magnetic particles.   
     
     
         17 . The system of  claim 16 , wherein the magnetic particles in the region have an average diameter of between 50 and 1000 microns. 
     
     
         18 . The apparatus of  claim 16 , wherein the magnetic particles contain neodymium, iron, and boron. 
     
     
         19 . The apparatus of  claim 16 , wherein the substrate is configured to rotate about an axis. 
     
     
         20 . The apparatus of  claim 16 , wherein the substrate is attached to a gear.