Researchers at UF AMSLab recently produced a Physically Unclonable Function (PUF) with less than 1.2% native instability by leveraging the resistance variation of metal vias. The target performance was achieved without the use of stabilization techniques.
![Metal Via Resistance PUF](https://maghari.ece.ufl.edu/wp-content/uploads/sites/21/2019/06/MVR_PUF.png)