S-ALSA reduces energy and stops data leaks in IoT memory
S-ALSA: Co-Design of Adiabatic Logic-based Sensing and Balanced Bit-Cells for Secure and Energy-Efficient MRAM
Hardware Architecture
Summary
Reading data from MRAM, a type of memory used in IoT devices, usually wastes a lot of energy and can leak secret information through side-channel attacks. The authors designed a new memory sensing approach called S-ALSA that saves up to 80% energy and stops attackers from learning secret keys by balancing electric currents and recovering charge. Their design works with existing MRAM technologies and was tested on small memory blocks. This work shows it is possible to make IoT memory both secure and energy-efficient at the same time.
What this means in practice
- •For iot device engineers: Design memory sensing circuits that reduce energy use and prevent side-channel attacks on IoT system memory.
- •For hardware security teams: Implement memory readout methods that eliminate data-dependent power leakage to protect encryption keys in edge devices.
Authors
Wu Yang, Amit Degada, Himanshu Thapliyal
Abstract
Magnetoresistive Random Access Memory (MRAM) technologies such as Spin-Transfer Torque (STT-MRAM) and Spin-Orbit Torque assisted (SOT-STT-MRAM) offer nonvolatility and low leakage, making them attractive for IoT systems. However, conventional MRAM read circuits face two fundamental challenges: high dynamic energy consumption and vulnerability to side-channel attacks caused by data-dependent current variations in Magnetic Tunnel Junctions (MTJs). This paper presents a Secured Adiabatic Logic Sense Amplifier (SALSA) that addresses both challenges simultaneously through circuit-device co-design. S-ALSA combines structural current balancing via a 4T-2MTJ bit cell, which eliminates read current asymmetry at the storage level, with dynamic power equalization via adiabatic charge recovery in the sensing circuit. The proposed architecture supports both STT-MRAM and SOT-STT-MRAM. Case studies using 4x4 MRAM macros shows up to 80% energy savings over conventional Pre-Charge Sense Amplifiers (PCSA) across IoT frequencies. Correlation Power Analysis (CPA) attacks on PRESENT-80 encryption confirm complete suppression of key leakage when S-ALSA is combined with a balanced bit cell. This work establishes a unified framework where energy efficiency and hardware security are achieved simultaneously, enabling secure and low-power IoT memory design.