AuthLog

AuthLog is an IoT-based smart access control system that unifies embedded hardware, cloud infrastructure, and mobile into a single secure architecture. An STM32 Nucleo-64 F401RE microcontroller handles RFID/NFC acquisition and local hardware management, while an ESP8266 module provides Wi-Fi connectivity and communicates with a Supabase backend over HTTPS. Authentication happens in real time via REST API requests over TLS 1.2, with every access event automatically logged to a PostgreSQL database. A Time-of-Flight distance sensor adds proximity detection, activating the system only when a user is physically present — improving both usability and energy efficiency. A cross-platform React Native mobile app completes the stack, supporting user registration, authentication, and direct NFC UUID writing from a smartphone, removing the need for physical RFID badges entirely.

Bridging three radically different environments — a resource-constrained STM32 microcontroller, an ESP8266 Wi-Fi module, and a cloud PostgreSQL database — with reliable, low-latency TLS communication was the central engineering challenge. Memory budgets on the microcontroller were tight, TLS handshake overhead had to be minimized, and the system needed to fail securely when connectivity dropped. On the mobile side, implementing NFC UUID writing and synchronizing state with the backend in real time required careful coordination across the entire stack.

Winner of the 3rd place "Salvatore Di Bartolo" Award at ITIS "E. Fermi" of Giarre, and submitted to the 2025–2026 national STMicroelectronics contest. The final system demonstrated end-to-end secure access control — from NFC tap to cloud log — with sub-second authentication latency and seamless mobile enrollment.