Magnetic PUF with Predetermined Information Layer

Abstract

The invention adds a Physical Information Layer (“PIL”) to the magnetic particles within a matrix that creates an unclonable physical unclonable function “object.” The PIL assists in searching to find the combination that matches a pre-determined enrolled combination with additional information that includes a search index, which limits the range of data required to search in order to find a match in the enrolled database. The index could be a predetermined value that associates the random magnetic profile values to a list of enrolled values in a database. The additional information may include product or general information that needs to be easily communicated to a user of the PUF.

We claim: 
     
         1 . An physical unclonable function (“PUF”) object comprising:
 a magnetic matrix; 
 a Physical Information Layer (“PIL”), wherein the PIL is constructed from a material that does not substantially alter the static magnetic field created by the magnetic particles and matrix dielectric material. 
 
     
     
         2 . The PUF object of  claim 1 , wherein the PIL is capacitively detectable. 
     
     
         3 . The PUF object of  claim 1 , wherein the PIL is optically detectable. 
     
     
         4 . The PUF object of  claim 1 , wherein the PIL is acoustically detectable. 
     
     
         5 . The PUF object of  claim 1 , further comprising fiducials that are easily recognized by a reader to orient the enrollment of the magnetic profile of the PUF and the PIL. 
     
     
         6 . The PUF object of  claim 5 , wherein the fiducials are box-like structures. 
     
     
         7 . The PUF object of  claim 1 , wherein the material contains a conductor. 
     
     
         8 . The PUF object of  claim 7 , wherein the material contains aluminum or copper. 
     
     
         9 . A physical information layer added to a physical unclonable object with magnetic particles comprising:
 a material that does not substantially alter the static magnetic field created by the magnetized particles and matrix dielectric material, such as a non-ferrous conducting material including aluminum or copper; and   conducting elements, wherein each of the conducting elements in the PIL is substantially larger than the magnetic particles within the PUF.   
     
     
         10 . The physical information layer of  claim 9 , wherein the PIL is attached to a surface of a PUF. 
     
     
         11 . The physical information layer of  claim 10 , wherein the PIL is attached by an adhesive or bonded by sintering. 
     
     
         12 . A method of determining the image of a physical information layer (“PIL”) on a physical unclonable object (“PUF”) comprising:
 supplying an alternating current (“AC”) signal to one or more of the sensor conducting pads; 
 measuring the voltage in the region around the source; 
 
       coupling a portion of the energy from the sensor source pad to the PIL of the PUF object;
 allowing the signal to travel through the continuous conduction path of the PIL to each of the nearby sensor measurement pads; and 
 programmatically looping the signal through the source and measurement locations of the PIL to determine the image. 
 
     
     
         13 . The method of  claim 12 , wherein the AC signal is sinusoidal or any other time changing waveform that facilitates a substantial received signal. 
     
     
         14 . The method of  claim 12 , wherein the AC signal is square, impulsive, or triangular. 
     
     
         15 . The method of  claim 12 , wherein when the stimulus is applied at one pad, the received sinsusoidal wave amplitude at other pad locations is measured. 
     
     
         16 . The method of  claim 15 , wherein the received sinusoidal wave is filtered to reduce interference.