Physical Unclonable Functions in Integrated Circuit Chip Packaging for Security

Abstract

In the invention described, magnetic field characteristics of randomly placed magnetized particles are exploited by using the magnetic field fluctuations produced by the particles as measured by a sensor. The magnetized particles generate a complex magnetic field near the surface of an integrated circuit chip that can be used as a “fingerprint.” The positioning and orientation of the magnetized particles is an uncontrolled process, and thus the interaction between the sensor and the particles is complex. The randomness of the magnetic field magnitude and direction near the surface of the material containing the magnetic particles can be used to obtain a unique identifier for an item such as an integrated circuit chip carrying the PUF.

What is claimed is: 
     
         1 . An apparatus comprising:
 a substrate;   a plurality of pre-magnetized particles that have random orientations of magnetization and are randomly dispersed in the substrate; and   an integrated circuit chip,   wherein the substrate containing the plurality of pre-magnetized particles is formed into a housing that encapsulates the integrated circuit chip.   
     
     
         2 . The apparatus of  claim 1 , further comprising a non-volatile memory on the integrated circuit chip, wherein the non-volatile memory contains magnetic field profile data measured from the pre-magnetized particles. 
     
     
         3 . The apparatus of  claim 1 , wherein the pre-magnetized particles contain neodymium and iron and boron. 
     
     
         4 . The apparatus of  claim 1 , wherein the pre-magnetized particles contain samarium and cobalt. 
     
     
         5 . The apparatus of  claim 1 , wherein the average particle size diameter of the pre-magnetized particles is greater than 0.1 mm. 
     
     
         6 . The apparatus of  claim 1 , wherein the average particle size diameter of the pre-magnetized particles is greater than 0.001 mm. 
     
     
         7 . An apparatus comprising:
 a substrate;   a plurality of pre-magnetized particles that have random orientations of magnetization and are randomly dispersed in the substrate;   an integrated circuit chip; and   at least one sensor positioned in contact with the integrated circuit chip,   wherein the substrate containing the plurality of pre-magnetized particles is formed into a housing that encapsulates the integrated circuit chip and the at least one sensor.   
     
     
         8 . The apparatus of  claim 7 , further comprising a non-volatile memory on the integrated circuit chip, wherein the non-volatile memory contains magnetic field profile data measured from the pre-magnetized particles. 
     
     
         9 . The apparatus of  claim 7 , wherein the pre-magnetized particles contain neodymium and iron and boron. 
     
     
         10 . The apparatus of  claim 7 , wherein the pre-magnetized particles contain samarium and cobalt. 
     
     
         11 . The apparatus of  claim 7 , wherein the average particle size diameter of the pre-magnetized particles is greater than 0.1 mm. 
     
     
         12 . The apparatus of  claim 7 , wherein the average particle size diameter of the pre-magnetized particles is less than 0.1 mm. 
     
     
         13 . An apparatus comprising:
 a substrate;   a plurality of pre-magnetized particles that have random orientations of magnetization and are randomly dispersed in the substrate;   an integrated circuit chip; and   a non-volatile memory on the integrated circuit chip, wherein the integrated circuit chip is over-molded with the substrate containing the pre-magnetized particles, and the non-volatile memory contains magnetic field profile data measured from the pre-magnetized particles.   
     
     
         14 . The apparatus of  claim 13 , wherein the pre-magnetized particles contain neodymium and iron and boron. 
     
     
         15 . The apparatus of  claim 13 , wherein the pre-magnetized particles contain samarium and cobalt. 
     
     
         16 . The apparatus of  claim 13 , wherein the average particle size diameter of the pre-magnetized particles is greater than 0.1 mm. 
     
     
         17 . The apparatus of  claim 13 , wherein the average particle size diameter of the pre-magnetized particles is less than 0.1 mm. 
     
     
         18 . The apparatus of  claim 13 , wherein the integrated circuit chip is used in a printer or printer supply component, such as a toner cartridge.