Security Vulnerabilities of Emerging Nonvolatile Main Memories and Countermeasures

Emerging nonvolatile memory devices such as phase change memories and memristors are replacing SRAM and DRAM. However, nonvolatile main memories (NVMM) are susceptible to probing attacks even when powered down. This way, they may compromise sensitive data such as passwords and keys that reside in the NVMM. To eliminate this vulnerability, we propose sneak-path encryption (SPE), a hardware intrinsic encryption technique for memristor-based NVMMs. SPE is instruction set architecture independent and has minimal impact on performance. SPE exploits the physical parameters, such as sneak-paths in crossbar memories, to encrypt the data stored in a memristor-based NVMM. SPE is resilient to a number of attacks that may be performed on NVMMs. We use a cycle accurate simulator to evaluate the performance impact of SPE-based NVMM and compare against other security techniques. SPE can secure an NVMM with a ~1.3% performance overhead.