Physically Unclonable Functions (PUF) are a mechanism employed to ensure that third party manufacturers, or counterfeiters, cannot pass off unauthorized products as authentic. Various kinds of memory based PUFs exist, including Static Random Access Memory (SRAM) PUF, Latch PUF and Nanoscale PUFs based on memristive crossbars. USF inventors have harnessed the intrinsic geometric variations in the MRAM cells to build a novel and random PUF response with very low intra-distances. Within the MRAM, a row of cells is used for the PUF and a response is generated by first destabilizing the row and then allowing them to relax. The MRAM PUF instances are easily constructible as well as evaluable. No additional fabrication processes are required for them. The procedure can also be adopted to generate random numbers using MRAM technology.
Abstraction of the MRAM PUF Authentication Protocol and the PUF System