Today I released the video of a project I’ve been working on for a little while – it’s a smart door lock system built with a Raspberry Pi which secures a door (or cupboard, safe etc.) in your home or office with three distinct steps required to be completed before entry is granted.
The first step is the scanning of an RFID / NFC keyfob. The system recognises the keyfob and presents a welcome message with your name and mugshot on the little touchscreen LCD.
The second step requires you to enter your secret, 6-digit PIN using the touchscreen.
The third step requires you to have your mobile phone handy, as it uses a 3rd party web service to send a one-time passcode via SMS.
After all 3 hoops have been jumped through, the Raspberry Pi operates a relay switch via its GPIO ports to activate an electronic striker plate for 5 seconds, allowing the door to be opened.
I realise that this is not strictly three factor authentication, because two of the steps are “something you have”, ie. your keyfob and your phone. However, an intruder would need to steal both in order to gain access, and each can be cancelled remotely (either call up your mobile provider or call the administrator of the lock system to ban your fob’s code). So, if one was unavailable at short notice hopefully the other one would be.
The system is fully open-sourced on Github and can be modified to add/remove/change steps if you wish, for example by adding in a fingerprint reader or retina scanner.
There’s a text write-up of the project on the Switched On Network website, at: https://www.switchedonnetwork.com/2017/11/10/build-the-ultimate-door-security-system-with-three-factor-authentication/
UPDATE – 1st June 2018
I’m delighted to say that this project has won an award! It gained 2nd Prize in Elecromaker’s Connectivity Contest.
Read more at https://www.electromaker.io/contest/connectivity