Physical 2FA

Only the Board was used.

Connect the Board to PC/Laptop or power it up with Battary.

Offline Network & Storage: The Memento Camera programmable Baord is set up as its own Access Point, named MEMENTO_VAULT, so it does not require a home router to be operational. The user's data, such as their username, password, and up to four stored "views" of their physical key, is stored as a C++ struct in the board's RAM.

Embedded Web Pages: The HTML, CSS, and JavaScript for the interface, or the login page, camera scanner, and vault page, are stored directly in the program using PROGMEM, eliminating the need for memory or an SD card.

Client-Side Image Hashing: This is the heavy lifter of the program. When a photo is taken, the JavaScript running on the client's phone shrinks it down to a tiny 32x32 pixel grid, converts it to grayscale, and then converts it to a 1024-character string of 1s and 0s depending on brightness. It only sends this lightweight version of the image back to the ESP32.

Fuzzy Verification: The handleVerifyObj() function then takes this string and compares it against the four stored strings. The code also includes a 15% error tolerance, as lighting and angles will never be perfect twice. If it's close enough, a 5-minute window is granted to view the vault.

Complete Project Code

Detailed Project Description

Physical 2FA grants or denies access based on a credential and keeps an audit log of every attempt.

How It Works
1. A credential (card, tag, fingerprint, code, token) is presented and read.
2. It is checked against the stored list of authorised users.
3. On success the lock/relay is released and the event logged; on failure an alert is raised.
4. An admin interface manages users and views the log.

Key Components and Their Role
- ESP32: dual-core Wi-Fi + Bluetooth microcontroller that runs the firmware, reads the sensors and hosts the network connection.
- Bluetooth Low Energy: short-range low-power wireless link to a phone or browser.
- microSD card module: storage for logs, audio or images over SPI.
- Camera module: image sensor used for capture, streaming or computer vision.

Implementation Steps
1. Collect the components and study each module's datasheet (pin-out, voltage, interface).
2. Wire the circuit on a breadboard following the pin mapping; power sensors from the correct rail (3.3 V / 5 V).
3. Install ESP32, BLE, C++ and the required libraries; flash a minimal test sketch for each module separately.
4. Write the main firmware: read sensors → process → drive outputs / send data.
5. Configure network or cloud credentials and test communication end-to-end.
6. Calibrate thresholds, add error handling (reconnect, sensor time-out) and run a long-duration test.
7. Finalise on a PCB / enclosure and document wiring, code and results.

Key Features
- Credential-based access
- Admin user management
- Audit log
- Failed-attempt alerts

Expected Output
On completion the student will have a door/relay that opens only for authorised credentials, with every attempt recorded.

Deliverables
- Complete source code with comments
- Circuit diagram and pin mapping
- Project report with screenshots and results
- Demonstration-ready build