Injection-Molded Physical Unclonable Function

Abstract

A method of manufacturing a physical unclonable function is disclosed. A highly random distribution of magnetic particles within a thermoplastic polymer is created by magnetizing magnetizable particles in solid pellet feed material before feeding the solid pellets into an injection molding machine. Other devices and processes are disclosed.

1 . A method of manufacturing a physical unclonable function comprising:
 combining feed material containing plastic and magnetizable particles that are not magnetized to form a solid pellet feed material;   magnetizing the particles in the solid pellet feed material to make pre-magnetized solid pellet feed material;   feeding the pre-magnetized solid pellet feed material into an injection molding machine; and   forming the feed material into an injection-molded physical unclonable function.   
     
     
         2 . The method of  claim 1 , wherein the magnetizable particles contain neodymium, iron, and boron. 
     
     
         3 . The method of  claim 1 , wherein the magnetizable particles contain samarium and cobalt. 
     
     
         4 . The method of  claim 1 , wherein the solid pellet feed material contains between ten and twenty percent, inclusive, by weight of magnetizable particles. 
     
     
         5 . The method of  claim 1 , wherein after feeding the pre-magnetized solid pellet feed material into an injection molding machine, the magnetizable particles are heated to below the Curie temperature of the magnetizable particles. 
     
     
         6 . The method of  claim 1 , wherein the magnetizable particles are flakes.