  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.
