Anti-counterfeiting Using Irregularities of Magnetic Flux Density

In recent years, many studies have used physical unclonable functions (PUFs), which are difficult to reproduce and highly secure, as a means to discriminate between counterfeit and authentic goods. Magnetic materials are widely used in items ranging from everyday goods to medical equipment and may be good PUF candidates given their versatility compared to conventional PUF technology and their potential to keep costs low. Therefore, we conducted experiments to compare changes in magnetic field caused by the presence of magnetic materials (magnetic paint, magnets). We used a magnetic field sensor embedded in a tablet PC to analyze the variability in magnetic characteristics of objects, which arise during magnet fabrication. It was found that magnets with the same shape could exhibit different magnetic characteristics, demonstrating the potential for magnetic materials to be used in anti-counterfeiting technology or as keys.