[Submitted on 26 Jul 2026]

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Abstract:Remote attestation (RA) is a lightweight security primitive for detecting software compromise on IoT devices. Traditional RA schemes require atomic, non-interruptible memory measurements, making them difficult to deploy alongside real-time workloads. SMARM addresses this limitation by measuring memory in a secret, shuffled block order, reducing the non-interruptibility period to the duration of a single block measurement. However, SMARM was originally designed for microkernel-based systems and has not been studied in RTOS-driven real-time environments.
In this work, we present the first systematic study of SMARM in real-time RTOS-based setups. We implement SMARM on commodity ARM TrustZone-M hardware running FreeRTOS and Zephyr, and introduce the Frequency Accuracy Ratio (FAR) to quantify the extent to which attestation can coexist with real-time execution under varying workloads. Our evaluation shows that SMARM's real-time compatibility is highly sensitive to block size: large blocks significantly degrade real-time availability, while small blocks incur substantial secure-storage overhead, limiting deployability on memory-constrained devices.
To address this limitation, we propose SMARM+, a family of enhanced SMARM variants consisting of SMARM+PRNG and SMARM+FPE. They are designed to reduce secure-storage requirements while preserving SMARM's security guarantees and real-time behavior. Our evaluation highlights the trade-off between secure-storage reduction, attestation runtime, and energy overhead, and provides guidance on selecting among SMARM, SMARM+PRNG, and SMARM+FPE for different deployment settings.

Submission history

From: Amarin Laohajirapan [view email]
[v1] Sun, 26 Jul 2026 14:46:54 UTC (6,022 KB)