Hardware Security of Emerging Non-Volatile Memory Devices under Imaging Attacks

The emerging non-volatile memory (NVM) devices are currently changing the landscape of computing hardware. However, their hardware security remains relatively unexplored in the field. This is a critical research problem because given that they are non-volatile, sensitive information may be vulnerable to various physical attacks unless properly encrypted. In this work, we investigated security vulnerability of two emerging non-volatile memory devices (STT-MRAM and RRAM) against the most commonly available, non-destructive physical attack - Scanning Electron Microscope (SEM) imaging. The central premise is that if any difference of memory cells in high resistance and low resistance (bit ‘1” and ‘0”) states can be detected in SEM, stored data could possibly leak or be stolen by adversaries. It is concluded that unless advanced elemental analysis techniques such as energy dispersive x-ray spectroscopy (EDX) are used, it is very unlikely that the bit information stored in these memory cells leak out by imaging attacks.