Secure STT-MRAM Bit-Cell Design Resilient to Differential Power Analysis Attacks

Spin-transfer torque magnetic random access memory (STT-MRAM) is a promising nonvolatile memory technology for various applications from low power to high-density memory. However, STT-MRAM is prone to power analysis attacks due to its asymmetric resistive states and switching behavior. This noninvasive class of attacks is a serious threat to system security. To reduce the correlation between the data and the power consumption of the memory, a countermeasure based on a resilient cell design with a symmetrical structure is proposed in this article. The standard cell and the proposed cell have been attacked and their resiliencies are compared. When attacked with a correlation power analysis (CPA), the proposed bit cell attacked with the hamming weight (HW) model is 100 times more resilient compared to the standard STT-MRAM cell. The proposed bit cell attacked with the hamming distance (HD) or the STT power models is more than 500 times more resilient compared to the standard STT-MRAM cell.