Data the and tampering are serious concerns as a ackers have aggressively begun to exploit weaknesses in current memory systems to advance their nefarious schemes. e storage industry is moving toward emerging non-volatile memories (NVM), including the spin-transfer torque magnetoresistive random access memory (STT-MRAM) and the phase change memory (PCM), owing to their high density and low power operation. e advent of novel memory technologies has led to new vulnerabilities including data sensitivity to magnetic eld and temperature uctuations and data persistence a er power down. In this paper, we propose SMART: a Secure Magnetoelectric Antiferromagnet-Based Tamper-Proof memory, which leverages unique properties of antiferromagnetic materials and offers dense, on-chip non-volatile storage. SMART memory is not only resilient against data con dentiality a acks seeking to leak sensitive information but also protects data integrity and prevents Denial of Service (DoS) a acks on the memory. It is impervious to power side-channel a acks, which exploit asymmetric reads/writes for '0' and '1' logic levels, and photonic side-channel a acks, which monitor photo-emission signatures from the chip backside. Further, the ultra-low power magnetoelectric switching coupled with the terahertz regime antiferromagnetic dynamics result in ∼ 4 orders lower energy-per-bit and ∼ 3 orders smaller latency for the SMART memory as compared to prior NVMs such as STT-MRAM and PCM.