Understanding and Characterizing Side Channels Exploiting Phase-Change Memories

Recent advances in nonvolatile memory (NVM), together with their performance-optimized architectural schemes, position NVMs as promising building blocks for future main memory. However, the security of such techniques has not been explored. This article performs the first study on information leakage threats in phase-change memories (PCM). We propose an attack framework, read-saw (R-SAW), that systematically investigates side channel vulnerabilities in representative read techniques under interline and intraline interleaving for multilevel cells. Our evaluation shows that the new side channels can accurately leak program secrets (e.g., crypto keys) and are extremely robust to noise. Our work highlights the need to understand microarchitecture security for emerging memory devices.