MAGNETIC PHYSICAL UNCLONABLE FUNCTION WITH MULTIPLE MAGNETIC COERCIVITIES

The use of two different magnetic coercivity materials in order to have both permanent and non-permanent content on the same security object is described. A security device is presented having a polymer matrix composite containing a uniform distribution of a low coercivity magnetic material such as, but not limited to, magnetite. In conjunction with this uniform background a random distribution of high coercivity magnetic material such as but not limited to an alloy of neodymium, iron, and boron (NdFeB) can be mixed within the first uniform background material to form a durable magnetic signature within the low coercivity uniform background. This can be achieved, for example, by compounding low and high coercivity materials in one compounding operation with one matrix material.