Attack resilient architecture to replace embedded Flash with STTRAM in homogeneous IoTs

Spin-Transfer Torque RAM (STTRAM) is an emerging Non-Volatile Memory (NVM) technology that provides better endurance, write energy and performance than traditional NVM technologies such as Flash. In embedded application such as microcontroller SoC of Internet of Things (IoT), embedded Flash (eFlash) is widely employed. However, eFlash is also associated with cost. Therefore, replacing eFlash with STTRAM is desirable in IoTs for power-efficiency. Although promising, STTRAM brings several new security and privacy challenges that pose a significant threat to sensitive data in memory. This is inevitable due to the underlying dependency of this memory technology on environmental parameters such as temperature and magnetic fields that can be exploited by an adversary to tamper with the program and data. In this paper, we investigate these attacks and propose a novel memory architecture for attack resilient IoT network. The information redundancy present in a homogeneous peer-to-peer connected IoT network is exploited to restore the corrupted memory of any IoT node when under attack. We are able to build a failsafe IoT system with STTRAM based program memory which allows guaranteed execution of all the IoT nodes without complete shutdown of any node under attack. Experimental results using commercial IoT boards demonstrate the latency and energy overhead of the attack recovery process. Keywords—IoT; security; STTRAM; memory; attack