Design and Evaluation of a Biometric IoT-Based Smart Lock System with Real-Time Monitoring and Alert Mechanisms

A smart door lock system based on IoT is presented which uses fingerprint biometric authentication, ESP32 microcontroller and Blynk IoT platform to provide a secure, user friendly and remote controllable access control solution. The proposed architecture replaces traditional locks with a real time biometric system that gives instant feedback through onboard display (OLED) and buzzer and remote monitoring and control through a mobile app. A new fail-safe mechanism is implemented: after 3 failed fingerprint attempts the system will lock out for 15 seconds and send instant alert to the authorized user’s smartphone. Performance test of the prototype shows fingerprint recognition time of around 1.0 second and door unlock time of 5 seconds, so it’s convenient to use. The system has a very low False Acceptance Rate (FAR) of 1.32% which means strong resistance to unauthorized access. The False Rejection Rate (FRR) is higher (around 26.32%) due to user error such as improper finger placement – so a usability issue to be addressed. The device can store up to 3 fingerprint profiles and gives visual/audible alert for all access events. This integration of IoT with biometric security not only enhances physical security but also user convenience, a modern smart-lock solution for smart home automation.