US Patent 12014534 Printed physical unclonable function patterns

A method is disclosed. For example, the method includes applying a clear coat layer on a substrate, drying the clear coat layer to form random microstructures in the clear coat layer, dispensing a printing fluid to print a graphical pattern on the clear coat layer, and generating a physical unclonable function (PUF) pattern by drying the printing fluid that fills the random microstructures formed in the clear coat layer.