RFID Smart Lock Using Arduino and Secure Authentication Algorithm

The RFID smart lock system operates by combining radio-frequency identification with microcontroller logic to physically actuate a locking mechanism. At the heart of the setup is the Arduino board, which continuously monitors the MFRC522 RFID reader module via Serial Peripheral Interface (SPI) communication. When an RFID ring, card, or tag is brought into close proximity to the MFRC522 module, its internal antenna uses electromagnetic fields to wirelessly power the tag's microchip and read its unique identifier (UID). The Arduino receives this data through the connecting wires and processes it using a secure authentication algorithm implemented via the Arduino IDE and the MFRC522 software library. If the scanned UID matches the pre-authorized cryptographic or hardcoded key values stored in the system, the Arduino changes the state of its digital output pin. This output sends a Pulse Width Modulation (PWM) control signal to the connected servo motor. The servo motor responds by rotating its shaft to a specific angle, physically pulling or turning a latch to unlock the door or mechanism. Once a set delay expires, the Arduino commands the servo motor to rotate back to its original locked position, securing the entry point again until the next valid authentication occurs.