Throughput Optimization of the ASCON Lightweight Cryptographic Algorithm on IoT Devices

ASCON is a lightweight authenticated encryption algorithm standardized by NIST for securing constrained IoT environments. This study presents the implementation of ASCON-128a in a practical IoT architecture, where the ESP32 serves as the central microcontroller at the IoT node and the Raspberry Pi 4 acts as the central microcontroller at the IoT gateway. The ESP32 is chosen for its low-power operation, integrated wireless communication, and suitability for embedded edge processing. At the same time, the Raspberry Pi 4 is selected to support higher computational demands and data aggregation at the network edge. To improve performance, optimization strategies such as CPU frequency scaling, IRAM execution, dual-core parallelism, and cache warm-up were applied on the ESP32, alongside frequency stabilization and cache warm-up on the Raspberry Pi 4. Experimental results indicate that the ESP32 achieves an encryption throughput of 2.42 MB/s, while the Raspberry Pi 4 reaches 124 MB/s. These results validate ASCON-128a as an efficient and secure cryptographic solution for heterogeneous IoT systems.