Experimental Study of Adversarial Magnetic Field Exposure Attacks on Toggle MRAM Chips

Systematic study of magnetoresistive random access memory (MRAM) chip behavior under external magnetic field exposure is important from security and reliability viewpoint. Some of the errors due to field exposure can possibly be exploited by miscreants as fault injection (FI) or denial-of-service (DoS) attacks on commercial-off-the-self (COTS) MRAM chips. In this study, we investigate the impact of exposure to strong external magnetic field on COTS toggle MRAM chips. In particular, we experimentally demonstrate: 1) change in current consumption during write/read operations and 2) occurrence of different types of errors, on different capacity MRAM chips, when exposed to external magnetic field. External magnetic field leads to corruption of stored data and temporary/permanent failures during read and write operations. Experiments are performed by applying magnetic fields from different directions of the chip. We observed that exposure to external magnetic field results in increase in chip read and chip write current by a range of ~1%–7% and ~1%–9%, respectively. In some cases, more than 95% of data corruption occurred instantaneously on field exposure. We also investigated the impact of field exposure on the nature of errors. As field exposure time increased the type of errors changed from temporary to permanent errors. We observed that switching failure from “1 s” to “0 s” is the dominating error type.