Practical Experiments to Evaluate Quality Metrics of MRAM-Based Physical Unclonable Functions
Arash Nejat, Frédéric Ouattara, Mohammad Mohammadinodoushan, Bertrand Cambou, K. Mackay, Lionel Torres
Abstract
Process variations in the manufacturing of digital circuits can be leveraged to design Physical Unclonable Functions (PUFs) that are extensively employed in hardware-based security. Different PUFs based on Magnetic Random-Access-Memory (MRAM) devices have been studied and proposed in the literature. However, most of these studies have been simulation-based, which do not fully capture the physical reality. We present experimental results on a PUF implemented on dies fabricated with a type of the MRAM technology namely Thermally-Assisted-Switching MRAM (TAS-MRAM). To the best of our knowledge, this is the first experimental validation of a TAS-MRAM-based PUF. We demonstrate how voltage values used for writing in the TAS-MRAM cells can make stochastic behaviors required for PUF design. The analysis of the obtained results provides some preliminary findings on the practical application of TAS-MRAM-based PUFs in authentication protocols. Besides, the results show that for key-generation protocols, one of the standard error correction methods should be employed if the proposed PUF is used.